THE   UNIVERSITY 

OF  ILLINOIS 

LIBRARY 


ir 


UNIVERSITY  OF  ILLINOIS 

Agricultural  Experiment  Station 


BULLETIN  No.  193 


SUMMARY  OF  ILLINOIS  SOIL 
INVESTIGATIONS 


BY  CYRIL  G.  HOPKINS,  J.  G.  MOSIEE,  AND  F.  C.  BAUEB 


URBANA,  ILLINOIS,  DECEMBER,  1916 


SUMMARY  OF  BULLETIN  No.  193 

1.  The  Illinois  Agricultural  Experiment  Station  has  been  conducting  exten- 
sive investigations  upon  the  improvement  of  Illinois  soils  for  the  past  fifteen  years 
by  means  of  a  systematic  soil  survey,  chemical  analysis,  and  culture  experiments. 

Pages  451-462 

2.  Field   investigations   have   been   conducted   upon   fifty   experiment   fields 
located  upon  representative  types  of  soil  in  various  parts  of  the  state.    Thirty-nine 
of  these  fields  are  in  operation  at  the  present  time.  Pages  454-459 

3.  Illinois  soils  exist  in  fourteen  great  soil  areas,  as  shown  on  the  colored 
map.  Pages  463-464 

4.  In  the  counties  covered  by  the  first  ten  soil  reports,  62  individual  soil 
types  have  been  discovered.     These  types  are  extremely   diverse   and   for   con- 
venience  are   grouped   into   six   classes;    namely,  prairie,   timber,   terrace,   ridge, 
swamp  and  bottom-land,  and  residual  soils.  Pages  464—465 

5.  The  fertility  invoices  of  the  individual  soil  types  show  a  great  variation 
in    the    content    of    the    essential    plant-food    elements.     Illinois  soils    may    be 
deficient  in   one   or  more   of   five  plant-food   elements;    namely,   nitrogen,   phos- 
phorus,  potassium,   calcium,   and  magnesium, — and   they   may  be   either   acid   or 
alkaline.     Thus  the  problem  of  maintaining  the  fertility  of  the  soil  is  sometimes 
complicated,  tho  usually  limited  essentially  to  the  application  of  limestone  and  phos- 
phorus and  the  turning  under  of  nitrogenous  organic  matter.  Pages  465-467 

6.  As  a  rule,  the  results  of  the  field  experiments  harmonize  with  the  informa- 
tion given  by  the  chemical  composition  of  the  soil.     They  have  shown:     (1)    that 
the  maintenance  of  organic  matter  and  nitrogen  is  the  greatest  practical  problem 
of  the  Illinois  farmer;   (2)  that  phosphorus  is  the  one  element  of  plant  food  that 
is  most  universally  deficient;  and  (3)  that  limestone  must  be  supplied  in  abundance 
to  many  soils  before  they  can  be  permanently  improved.  Pages  467-483 

7.  On  the  ordinary   corn-belt   soil,  proper  treatment  has  produced   a   total 
value  for  one  rotation  (1911-1914)  of  $98.58,  as  contrasted  with  $65.00  where  no 
treatment  was  given.     One  dollar  invested  in  rock  phosphate  has  paid  returns  as 
follows:    first  rotation,  $1.18;  second  rotation,  $1.62;  third  rotation,  $2.70. 

Pages  473-475 

8.  Southern  Illinois  prairie  land  has  been  improved  by  proper  soil  treatment 
so  that  the  total  increase  over  untreated  land  has  been  207  percent.  Page  477 

9.  On  peat  soil,  potassium  has  increased  corn  yields  by  more  than  30  bushels 
per  acre.  Page  482 

10.  On  sand  soils,  during  six  years  the  value  of  the  crops  per  acre  has  been 
increased  $73.37  by  nitrogen  and  only  22  cents  by  phosphorus  in  addition.    Page  482 

11.  Every  farmer  should  practice  a  high-grade  system  of  permanent  agricul- 
ture.   This  is  made  possible  by  good  crop  rotation  and  the  application  of  materials 
economically  supplementing  soil  deficiencies.  Page  483 

Available  publications  relating  to  Illinois  soil  investigations.  Page  484 


SUMMARY  OF  ILLINOIS  SOIL 
INVESTIGATIONS 

BY  CYRIL  G.  HOPKIXS,  CHIEF  ix  AGRONOMY  AND  CHEMISTRY 
J.  G.  MOSIER,  CHIEF  IN  SOIL  PHYSICS,  AND 
F.  C.  BAUER,  ASSOCIATE  IN  SOIL  FERTILITY 


The  wealth  of  Illinois  is  in  her  soil,  and  her  strength  lies  in  its  intelligent 
development. — DRAPER. 

The  purpose  of  this  bulletin  is  to  summarize  the  results  of  the 
soil  investigations  which  have  been  carried  on  by  the  Illinois  Agri- 
cultural Experiment  Station,  in  order  that  the  farmers  and  landown- 
ers may  know  of  the  progress  being  made,  and  thus  hasten  the  adop- 
tion of  systems  of  farming  that  will  increase  and  permanently  main- 
tain the  productive  capacity  of  Illinois  soils,  instead  of  decreasing 
their  fertility,  as  is  done  under  the  most  common  practices. 

NATURE  AND  EXTENT  OF  INVESTIGATIONS 

The  Illinois  Agricultural  Experiment  Station  began  to  investigate 
the  soils  of  the  thirty-six  million  acres  of  land  within  the  borders  of 
the  state  in  1901,  with  an  appropriation  from  the  General  Assembly 
of  $10,000  per  annum  for  two  years.  In  other  words,  this  huge  task 
was  begun  with  an  annual  appropriation  of  one  cent  for  each  thirty- 
six  acres.  The  growth  of  the  work  has  since  been  so  rapid  and  its 
value  so  evident  that  there  is  now  an  appropriation  of  one  cent  an- 
nually for  about  every  four  acres. 

The  purpose  of  these  investigations  has  been  five-fold,  for  the  in- 
telligent use  of  Illinois  soils  requires  definite  knowledge  in  regard  to : 
(1)  the  plant-food  requirements  of  the  crops  to  be  produced;  (2)  the 
total  stock  of  plant  food  contained  in  the  soil ;  (3)  the  availability  of 
the  plant-food  elements  by  practical  methods  of  farming;  (4)  the 
most  practical  economical  methods  of  supplementing  or  increasing  the 
plant  food  in  the  soil;  and  (5)  the  systems  of  farming  that  will  most 
profitably  and  permanently  maintain  the  productive  capacity  of  the 
soil.  Such  knowledge  has  been  rendered  possible  by  means  of  sys- 
tematic soil  survey,  chemical  analysis,  and  culture  experiments. 

SOIL  SURVEY 

The  soil  survey  has  furnished  much  valuable  information :  first, 
by  establishing  by  a  general  survey  the  existence  of  extensive  soil  types 
in  the  great  soil  areas  into  which  the  state  is  naturally  divided ;  and 

451 


452  BULLETIN  No.  193  [December, 

second,  by  determining  by  detailed  county  survey  the  soil  types  upon 
every  farm  in  the  state.  This  detail  survey  when  completed  and 
mapped  will  give  every  farmer  and  landowner  definite  information 
concerning  the  soils  upon  his  own  farm,  even  down  to  ten-acre  units 
or  less. 

A  map  showing  accurately  the  location  and  extent  of  the  different 
soil  types,  with  their  principal  variations  and  limits,  is  essentially  the 
objective  of  the  soil  survey.  During  the  fifteen  years  the  work  has 
been  in  progress,  a  general  survey  of  the  state  has  been  made  and  more 
than  sixty  counties  have  been  completely,  or  almost  completely,  sur- 
veyed in  detail,  in  such  order  that  every  unsurveyed  county  borders 
two  or  more  surveyed  counties.  At  the  present  rate  of  progress  the 
detail  survey  of  the  state  should  be  completed  in  six  or  seven  years. 

CHEMICAL  ANALYSIS 

Chemical  analysis  of  the  soil  has  furnished  an  accurate  invoice 
of  the  total  amounts  of  the  different  essential  elements  of  fertility 
contained  in  the  soil  to  a  depth  to  which  plant  roots  normally  extend. 
For  obvious  reasons  this  soil  depth  is  divided  into  three  strata :  the 
surface,  the  subsurface,  and  the  subsoil.  The  surface  soil  extends  to 
the  depth  of  good  plowing  (0  to  6%  inches)  and  is  that  part  with 
which  the  farm  manure,  limestone,  phosphate,  or  other  fertilizer  is 
incorporated,  and  that  part  which  must  be  depended  upon  largely  to 
furnish  the  necessary  plant  food  for  the  production  of  crops.  The 
subsurface  soil  lies  between  the  depths  of  6%  and  20  inches,  and  may 
be  stirred  by  subsoiling.  The  subsoil  extends  from  20  to  40  inches. 

After  a  county  has  been  surveyed,  representative  samples  of  every 
soil  type  established  by  the  survey  are  secured  from  each  of  the  three 
strata.  Great  care  is  used  in  every  case  to  avoid  the  taking  of  samples 
that  would  not  in  every  way  be  true  to  the  soil  type.  Old  stack  yards 
and  feed  lots  and  fields  that  have  been  heavily  manured  or  fertilized 
are  avoided,  and  all  other  abnormalities  are  guarded  against.  When 
a  suitable  area  has  been  selected,  many  soil  samples  are  drawn  at  dif- 
ferent places  some  rods  apart.  The  samples  of  each  stratum  are  thoroly 
mixed  and  about  ten  pounds  of  the  mixed  soil  is  then  bagged  and 
given  an  official  number.  An  exact  record  is  also  kept  of  the  location 
from  which  the  samples  have  been  taken.  Extensive  types  are  sam- 
pled many  times  in  the  county ;  less  extensive  types  are  sampled  as 
they  occur. 

The  soil  samples  thus  secured  are  sent  to  the  Station  laboratories, 
where  they  are  prepared  for  analysis  by  thoro  air-drying  and  pulver- 
izing. The  pulverizing  consists,  first,  in  reducing  the  entire  sample  to 
such  condition  that  it  will  pass  thru  a  millimeter  sieve  (25  holes  to 
the  linear  inch),  a  record  being  kept  of  the  amount  of  pebbles,  rock, 
and  other  material  that  will  not  pass  thru ;  and  for  certain  determina- 


1916\ 


SUMMARY  OF  ILLINOIS  SOIL  INVESTIGATIONS 


453 


tions  it  consists  further  in  reducing  about  100  grams  of  this  soil  to 
such  fineness  that  it  will  all  pass  thru  a  sieve  having  10,000  holes  to 
the  square  inch.  In  all,  nine  different  determinations  are  then  made, 
as  follows:  for  dry  matter,  for  total  organic  carbon,  total  nitrogen, 
total  phosphorus,  total  potassium,  total  calcium,  total  magnesium, 
total  inorganic  carbon  for  the  presence  of  limestone,  and  for  soil 
acidity,  these  being  the  most  important  plant-food  elements  and  soil 
characteristics  which  are  more  or  less  under  the  control  of  the  farmer. 
After  the  soil  is  analyzed,  the  reserve  is  stored  away  in  vaults  for  any 
possible  future  use,  such,  for  example,  as  determining  the  degree  of 
solubility  in  various  solvents,  in  case  conditions  should  ever  justify 
such  work. 


PHOSPHORUS 
1,200  MG. 


"^^ 


SCALE     I  MG,=  I  LB. 


FIG.  1. — PROPORTIONATE  AMOUNTS  OP  POTASSIUM  AND  PHOSPHORUS  IN  THE 
SURFACE  SOIL  OF  AN  ACRE  OF  TYPICAL  CORN-BELT  SOIL 


All  results  of  the  chemical  analyses  are  reported  on  the  acre  basis, 
assuming  the  weight  of  the  surface  soil  to  be  2  million  pounds ;  the 
subsurface,  4  million  pounds ;  and  the  subsoil,  6  million  pounds.  In 
the  case  of  sand  soils,  however,  2i/2  million,  5  million,  and  iy2  million 
pounds,  respectively,  are  used  as  the  bases,  and  for  peat  soils,  1  million, 
2  million,  and  3  million  pounds,  on  account  of  the  difference  in  the 
specific  gravities  of  these  types.  The  results  are  so  reported  because 
they  are  easily  understood  and  readily  compared  in  practical  applica- 
tion, and  they  are  also  scientifically  exact. 


454  BULLETIN  No.  193  [December, 

Since  the  beginning  of  the  work  about  7,000  samples  of  soil  have 
been  collected  from  various  parts  of  the  state,  and  of  this  number 
approximately  4,600  have  been  analyzed.  At  the  present  rate  of  col- 
lecting and  analyzing  the  samples  (about  five  counties  a  year),  twelve 
to  thirteen  years  will  be  required  to  complete  the  work  for  the  entire 
state. 

EXPERIMENT  FIELDS 

Culture  experiments  have  been  conducted  by  the  University  upon 
experiment  fields  established  in  all  sections  of  the  state  upon  im- 
portant and  representative  soil  types.  The  fields  are  so  operated  as 
to  give  the  farmer  positive  information  upon  practical,  economical, 
and  permanent  systems  of  soil  management.  Such  experiments  have 
been  conducted  on  fifty  fields  in  various  parts  of  the  state,  thirty-nine 
of  which  are  in  operation  at  the  present  time. 

The  first  fields  were  established  in  the  summer  and  fall  of  1901 
upon  rented  tracts  of  land.  More  or  less  difficulty  prevailed  at  that 
time  in  securing  suitable  tracts  because  in  many  cases  the  farmers  had 
little  interest  or  confidence  in  the  work;  but  this  indifference  gradu- 
ally changed  to  real  interest,  and  at  the  end  of  six  years  the  University 
was  operating  twenty  fields. 

By  1908  the  value  of  such  fields  for  purposes  of  investigation 
and  demonstration  of  soil  improvement  methods  began  to  impress 
many  people.  Suitable  tracts  of  land  for  such  experiments  were  then 
offered  and  donated  permanently  to  the  University  by  local  communi- 
ties and  individuals,  and  from  thenceforth  the  University  has  estab- 
lished no  field  except  upon  permanently  deeded  land.  In  recent  years 
many  more  such  tracts  have  been  offered  than  could  be  accepted. 

In  establishing  a  permanent  field,  it  is  the  policy  of  the  Univer- 
sity to  choose  a  location  where  the  results  will,  in  every  respect,  be  of 
the  greatest  value  to  the  community.  The  land  above  all  must  be 
uniform  in  order  that  practical  and  trustworthy  information  may  be 
secured.  It  must  represent  an  extensive  soil  type  so  that  the  results 
secured  from  different  systems  of  farming  will  be  widely  applicable 
to  the  conditions  of  the  community.  It  should  be  upon  a  main  thoro- 
fare  and  within  easy  walking  distance  from  railroad  stations  so  that 
it  will  be  easily  accessible  to  visitors. 

As  new  and  permanent  fields  have  been  established,  a  number  of 
the  older  temporarily  rented  fields  in  the  same  general  locality  have 
been  given  up,  sometimes  because  the  lease  expired  and  could  not  be 
renewed.  Fields  that  have  been  discontinued  were  located  near  the 
following  places :  Myrtle,  Ogle  county ;  Tampico,  Whiteside  county ; 
Green  Valley,  Tazewell  county;  Lincoln,  Logan  county;  Manito  (old 
field),  Mason  county;  Sibley,  Ford  county;  Auburn,  Sangamon 
county;  Manito  (new  field).  Tazewell  county;  Mascoutah,  St.  Hair 


j.9.76]  SUMMARY  OF  ILLINOIS  SOIL  INVESTIGATIONS  455 

county;  Vienna  (fertility  field),  Johnson  county;  and  Momence,  Kan- 
kakee  county. 

At  the  present  time  twelve  rented  fields  are  still  being  operated, 
six  of  them  temporarily  and  six  with  perpetual  leases.  Some  of 
the  former  will  undoubtedly  have  to  be  discontinued  sooner  or  later 
on  account  of  the  impossibility  of  securing  permanent  possession  of 
the  land.  These  temporary  fields  are  located  near  the  following  places : 
Antioch,  Lake  county;  DeKalb,  DeKalb  county;  Fairfield,  Wayne 
county;  Galesburg,  Knox  county;  McNabb,  Putnam  county;  and 
Rockford,  Winnebago  county.  The  six  fields  which  may  be  perma- 
nently retained  by  the  University  are  located  near  Odin,  Marion 
county;  Cutler,  Perry  county;  Bloomington,  McLean  county;  Du- 
Bois,  Washington  county ;  Union  Grove,  Whiteside  county ;  and  Vir- 
ginia, Cass  county. 

In  addition  to  the  six  permanently  leased  fields,  the  University 
has  secured  possession  of  twenty-seven  fields  so  long  as  they  are 
used  for  agricultural  experimentation  or  demonstration.  The  perma- 
nent fields  now  owned  by  the  University  or  controlled  without  rental 
expense  are  located  as  follows : 

(1)  Aledo  experiment  field,  Mercer  county,  about  one-half  mile 
west  of  the  railway  station  at  Aledo.     The  land  was  purchased  and 
donated  by  the  business  men  and  landowners  of  Aledo  and  vicinity, 
in  part  thru  the  efforts  of  William  and  Vashti  College. 

(2)  Carlinville  experiment  field,  Macoupin  county,  part  of  an 
eighty-acre  tract  011  which  Blackburn  College  is  located.    The  perma- 
nent possession  and  use  of  this  land  was  a  direct  donation  from  Black- 
burn College. 

(3)  Carthage  experiment  field,  Hancock  county,  within  the  cor- 
porate limits  of  Carthage,  about  five  blocks  south  of  the  courthouse. 
The  land  was  purchased  and  donated  by  the  business  men  and  land- 
owners of  Carthage  and  vicinity,  partially  on  account  of  their  interest 
in  Carthage  College. 

(4)  Clayton  experiment  field,  Adams  county,  adjoining  the  town 
of  Clayton.    The  field  is  about  five  blocks  south  of  the  railway  station, 
and  reached  by  a  concrete  walk.    The  land  was  donated  by  the  citizens 
of  Clayton  and  vicinity. 

(5)  Dixon  experiment  field,  Lee  county,  on  the  north  side  of  the 
interurbaii  railroad  about  two  miles  \vest  of  Dixon.     The  land  was 
purchased  and  donated  by  the  citizens  of  Dixon  and  vicinity. 

(6)  Enfield  experiment  field,  White  county,  three-quarters  of  a 
mile  northeast  of  the  town  of  Enfield.    The  land  was  purchased  and 
donated  by  about  six  hundred  citizens  of  White  county. 

(7)  Ewing  experiment  field,  Franklin  county,  about  one-half 
mile  northeast  of  the  village  of  Ewing.    The  land  was  purchased  and 
donated  by  Ewing  College  with  the  assistance  of  friends  of  that 
institution. 


456 


BULLETIN  No.  193 


1916]  SUMMARY  OF  ILLINOIS  SOIL  INVESTIGATIONS  457 

(8)  Hartsburg  experiment  field,  Logan  county,  about  one-half 
mile  east  of  the  village  of  Hartsburg.    This  land  was  donated  by  the 
Scully  estate. 

(9)  Joliet  experiment  field,  Will  county,  three  miles  northwest 
of  Joliet,  on  the  Joliet-Plainfield  wagon  road  and  the  Aurora-Joliet 
interurban  line.    The  land  was  purchased  and  donated  by  Will  county. 

(10)  Kewanee  experiment  field,  Henry  county,  about  midway 
between  Kewanee  and  Galva  on  the  Galva  and  Kewanee  electric  line. 
The  car  stops  at  Midland  about  one-half  mile  south  of  the  field.    The 
land  was  purchased  and  donated  by  the  citizens  of  Kewanee,  Galva, 
and  vicinity. 

(11)  LaMoille  experiment  field,  Bureau  county,  about  one  mile 
south  of  the  corporate  limits  of  LaMoille.    The  land  was  donated  by 
Mrs.  Anna  Norris  Kendall,  and  was  a  part  of  the  farm  on  which  her 
own  residence,  "Elizabeth  Cottage,"  is  located. 

(12)  Lebanon  experiment  field,    St.    Clair  county,   about  five 
blocks  south  of  the  main  street  of  Lebanon.    The  land  was  purchased 
and  donated  by  McKendree  College,  the  purchase  price  being  con- 
tributed for  the  purpose  by  Governor  Charles  S.  Deneen,  an  alumnus 
and  trustee  of  McKendree  and  at  the  time  an  ex-officio  trustee  of  the 
University  of  Illinois. 

(13)  Minonk  experiment  field,  Woodford  county,  one  mile  west 
of  Minonk.    This  land  was  donated  by  Mr.  and  Mrs.  Bela  M.  Stoddard, 
of  Minonk. 

(14)  Mount  Morris  experiment  field,  Ogle  county,  immediately 
adjoining  the  residence  district  on  the  south  side  of  Mount  Morris. 
The  land  was  purchased  and  donated  by  Mount  Morris  College  and 
citizens  of  Mount  Morris  and  vicinity. 

(15)  Newton  experiment  field,  Jasper  county,  about  one  and 
one-half  miles  northwest  of  Newton.     The  land  was  purchased  and 
donated  by  Jasper  county  and  the  citizens  of  Newton  and  vicinity. 

(16)  Oblong  experiment  field,    Crawford  county,   five  blocks 
south  of  the  station  at  Oblong.    The  land  was  purchased  and  donated 
by  the  citizens  of  Oblong  and  vicinity. 

(17)  Oquawka  experiment  field,  Henderson  county,  about  one 
mile  northeast  of  the  C.  B.  &  Q.  station  at  Oquawka.    The  field  was 
donated  by  Mr.  Alex  Moir  and  others. 

(18)  Pana  experiment  field,  Christian  county,  just  north  and 
east  of  Pana,  one  mile  from  the  Big  Four  and  Illinois  Central  passen- 
ger station.    This  field  was  donated  by  the  late  Captain  Kitchell,  of 
Pana. 

(19)  Raleigh   experiment  field,    Saline   county,    one-half   mile 
south  of  Raleigh,  on  land  purchased  and  donated  by  citizens  of  Ra- 
leigh, Galatia,  and  vicinity. 


458  BULLETIN  No.  193  [December, 

(20)  Sidell  experiment  field,  Vermilion  county,  one  mile  directly 
east  of  Sidell.    The  land  was  purchased  and  donated  by  the  citizens 
of  Sidell  and  vicinity. 

(21)  Sparta  experiment  field,  Randolph  county,  immediately 
north  of  the  city  of  Sparta.    The  land  was  purchased  and  donated  by 
the  citizens  of  Sparta  and  vicinity. 

(22)  Spring  Valley  experiment  field,  Bureau  county,  about  one- 
half  mile  from  the  business  part  of  Spring  Valley.    The  land  was  do- 
nated by  the  vocational  township  high  school  of  Spring  Valley. 

(23)  Toledo  experiment  field,  Cumberland  county,  about  one- 
half  mile  south  of  the  courthouse  at  Toledo.    The  land  was  purchased 
and  donated  by  the  county. 

(24)  Urbana  experiment  field,  Champaign  county,  on  the  Uni- 
versity farm.    Part  of  this  field  has  been  under  continuous  experiment 
for  thirty-seven  years.    So  far  as  is  known,  it  is  the  oldest  experiment 
field  in  the  United  States  on  which  the  originally  planned  experiments 
are  still  in  progress.     It  is  unquestionably  the  most  valuable  land 
within  the  borders  of  the  state,  considering  the  annual  lesson  it  now 
presents  to  the  agricultural  world. 

(25)  Brookport-Unionville  experiment  field,  Massac  county,  ad- 
joining the  village  of  Unionville,  five  miles  east  of  Brookport,  on  land 
purchased  and  donated  by  citizens  of  Massac  county  and  southern 
Pope  county.    This  experiment  field  is  located  on  the  most  southern 
table  land  of  the  state,  within  five  miles  of  the  mouth  of  the  Tennessee 
river,  which  flows  "northward  from  Alabama  and  is  said  to  modify 
appreciably  the  temperature  of  the  Ohio  river  below  Paducah  and 
Brookport. 

(26)  Vienna  experiment  field,  Johnson  county,  about  one  mile 
south  of  Vienna.1     This  field  is  rolling  hill  land  and  is  devoted  to  a 
special  study  of  surface  washing  and  methods  for  its  prevention.    On 
part  of  the  field  destructive  erosion  is  permitted  to  continue,  as  an 
object  lesson.    The  land  cost  $20  an  acre. 

(27)  "West  Sal  em.  experiment  field,  Edwards  county,  three-quar- 
ters of  a  mile  southwest  of  the  station  at  "West  Salem.     The  land  was 
purchased  and  donated  by  the  citizens  of  "West  Salem  and  vicinity. 

Thirty-six  of  the  thirty-nine  fields  listed  here  are  operated  pri- 
marily to  give  Illinois  farmers  the  most  complete  information  possible 
upon  systems  of  farming  that  will  permanently  maintain  or  increase 
the  productive  capacity  of  their  soils.  Of  the  three  remaining,  the  fields 
near  DeKalb  in  DeKalb  county,  and  near  Fairfield  in  Wayne  county 
are  given  over  mainly  to  crop  investigations,  and  the  Vienna  field,  as 
has  been  stated,  is  devoted  to  the  study  of  methods  of  preventing  soil 
washing  and  erosion.  The  distribution  of  those  experiments  fields  is 
shown  by  Fig.  2. 

'This  tract  is  in  addition  to  the  leased  land  mentioned  in  the  list  of  discon- 
tinued fields,  page  454. 


1916]  SUMMARY  OF  ILLINOIS  SOIL  INVESTIGATIONS  459 

PLAN  AND  METHODS  OF  FIELD  INVESTIGATIONS 

Each  experiment  field  contains  on  the  average  about  twenty  acres 
of  land,  divided  into  series  which  correspond  to  the  different  fields 
upon  a  farm.  Each  series  is  further  divided  into  smaller  areas, 
usually  ten  fifth-acre  plots,  and  these  are  treated  in  such  a  manner 
that  positive  information  can  be  secured  in  regard  to  the  needs  of  the 
soil.  Untreated  plots  are  retained  as  checks  in  order  to  determine  the 
effect  of  every  kind  of  soil  treatment  applied. 

Crops  are  grown  upon  these  fields  in  a  definite  rotation.  On  some 
fields  two  or  more  rotations  are  being  tried.  There  are  usually  a 
sufficient  number  of  series  so  that  the  crops  of  the  main  rotation  are 
represented  every  year.  The  crops  grown  are  those  common  to  the 
locality  and  include  wheat,  corn,  oats,  barley,  red  clover,  alsike,  sweet 
clover,  alfalfa,  cowpeas,  soybeans,  vetch,  timothy,  and  potatoes. 

Altho  there  may  be  a  number  of  ways  of  meeting  the  needs  of  the 
soil  with  respect  to  better  production,  the  Illinois  Agricultural  Ex- 
periment Station  makes  use  largely  of  natural  methods  and  natural 
materials.  Instead  of  applying  expensive  complete  fertilizers,  which 
may  produce  a  more  or  less  rapid  response,  wide  use  is  made  of  such 
natural  materials  as  farm  manure,  legume  crops,  crop  residues,  ground 
limestone  (both  ordinary  and  dolomitic,  each  of  which  is  found  in 
abundance  in  Illinois),  steamed  bone  meal  (a  farm  product),  and 
ground  natural  raw  rock  phosphate.  Abundant  information  points  to 
the  fact  that  in  the  long  run  and  under  normal  conditions  the  use  of 
these  materials  in  well  planned  systems  of  farming  usually  proves  to 
be  the  most  practical  and  economical  method  of  soil  improvement.  In 
some  comparative  experiments  and  on  some  abnormal  soils,  purchased 
nitrogen,  manufactured  acid  phosphate,  potassium  salts,  and  other 
commercial  fertilizers  are  used. 

In  order  that  the  reader  may  better  understand  the  operation  of 
a  typical  experiment  field,  the  arrangement  and  methods  used  on  the 
field  located  at  Urbana  are  here  described.  The  accompanying  dia- 
gram of  the  field  shows  the  manner  in  which  the  series  and  individual 
plots  are  arranged.  The  treatment  given  each  plot  and  the  method 
of  numbering  is  indicated  thereon.  Each  plot  covers  exactly  one- 
tenth  of  an  acre. 

A  combination  rotation  is  practiced  which  is  well  suited  to  the 
farming  conditions  of  this  region  of  the  state.  Corn,  oats,  clover,  and 
wheat,  in  the  order  named,  rotate  once  completely  over  four  fields 
while  a  fifth  field  is  in  alfalfa.  After  the  four  crops  have  been  rotated 
over  the  four  fields  for  five  years,  the  alfalfa  is  changed  to  one  of  the 
other  fields,  and  the  old  alfalfa  field  is  then  used  in  the  four-year 
rotation.  This  is  repeated  until  the  alfalfa  again  occupies  the  same 
field.  The  whole  rotation  will  cover  a  period  of  twenty-five  years. 


460 


BULLETIN  No.  193 


[December, 


So/ 

foi 

Soy 

«  4 

J^oj- 

J~o< 

fe^ 

S~ot 

5-0  f 

j-/o 

O 

ft 

M 

R 

M 

R 

M 

K 

M 

c^ 

1- 

L. 

t. 

u 

\_ 

IW*" 

P 

P 

P 

P 

L 

K 

4.01 

o 

+  02 
R 

4-03 
M 

4-04 
R 

M 

4-<U 

4-07 

M 

4-0  J 

R 

M 

4.10 
Cv 

L 

U 

L 

L 

L 

L 

M'*" 

P 

F 

P 

P 

L 

K 

K 

P 

-JO/ 
O 

302. 

R 

303 
M 

304 

M 

306 
K 

M 

R 

M 

f.v 

L 

L 

L 

U 

U 

u 

l^i  j- 

P 

F 

P 

r 

L 

K 

K 

10  I 

o 

202 

R 

203 
M 

2R 

M 

R 

207 
M 

*R 

2.0? 

*Cv 

L 

U 

U 

L 

L 

i 

M'^ 

P 

F 

P 

P 

L 

K 

K 

P" 

/"I 
0 

R 

103 
M 

104 
R 

/Of 

M 

R 

1  07 

M 

/o? 

'A' 

110 

Cv 

U 

U 

u 

L 

L 

L 

M'r 

P 

P 

F 

F 

U 

K 

K 

p.. 

Fm.  4. — DIAGRAM  OF  UEBANA  EXPERIMENT  FIELD 

0=No  treatment;  M^Manure;  Lc^Limestone ;  P;=Pliosphorus ;  E=Eesidues 
(corn  stalks,  straw  of  wheat  and  oats,  and  all  legumes  except  seed)  ;  K=Potassium; 
Cv=zCover  crop 


1916] 


SUMMARY  OF  ILLINOIS  SOIL  INVESTIGATIONS 


461 


As  may  be  noted  from  the  diagram,  two  different  systems  of  farm- 
ing are  practiced;  namely,  a  live-stock  system  and  a  grain  system. 
In  the  live-stock  system,  the  feed  grains  and  all  the  hay  and  forage 
(corn  stalks  and  straw)  are  used  for  feed  and  bedding.  The  resulting 
manure  is  returned  to  the  land  and  constitutes  the  important  source 
of  nitrogen  and  organic  matter  for  soil  improvement.  In  the  grain 
system,  the  nitrogen  and  organic  matter  are  maintained  by  plowing 
under  all  crop  residues  after  the  seed  is  removed  (corn  stalks,  the 
straw  from  wheat,  oats,  soybeans,  clover,  etc.,  and  some  cover  crops). 
Under  this  system,  the  grain,  the  alfalfa,  and  the  clover  or  other 
legume  seed  are  marketed.  Alfalfa  is  regarded  as  a  money  crop,  since 
sufficient  residues  are  provided  in  the  regular  four-year  rotation  to 
supply  the  needs  of  the  non-legumes  for  nitrogen. 


NONE      I 


FIG.  5. — POT  CULTURES  SHOWING  THE  EFFECT  OF  THE  PRESENCE  AND  ABSENCE 

OF  PLANT  FOODS 

(Observe  that  inoculated  clover  without  applied  nitrogen  grows  as  luxuriantly 
as  uninoculated  clover  supplied  with  commercial  nitrogen) 


In  both  systems  of  farming  there  are  check  plots  which  do  not 
receive  any  treatment.  The  only  benefits  the  soil  receives  are  those 
which  are  incidental  to  the  rotation.  Everything  is  removed  from  the 
land,  and  nothing  returned;  which  means  a  gradual  decrease  in  pro- 


462  BULLETIN  No.  193  [December, 

ductive  power  and  eventual  land  ruin.  The  purpose  of  these  plots  is 
to  show  by  comparison  the  value  of  the  treatment.  The  other  plots 
receive  additional  treatments  in  such  a  way  that  the  definite  needs  of 
the  soil  may  be  determined ;  whether  it  be  manure  or  residues  alone, 
or  lime  in  addition,  or  lime  and  phosphorous  in  addition,  that  must 
be  supplied  in  order  to  insure  greater  production.  To  two  plots  in 
the  series,  potassium  is  added  in  order  to  obtain  information  in  regard 
to  the  possible  need  for  that  element.  In  both  systems  of  farming, 
provision  is  made  for  the  maintenance  and  the  increase  of  those  ele- 
ments of  plant  food  and  those  physical  conditions  necessary  for  the 
best  plant  growth  as  indicated  by  the  soil  survey,  the  soil  analysis,  and 
other  sources  of  knowledge. 

VALUE  OF  INVESTIGATIONS 

The  value  of  these  investigations  as  the  results  are  disseminated 
is  to  make  clear  the  vital  facts  that  the  productive  power  of  the"  soil 
depends  upon  its  ability  to  feed  the  plant,  and  that  low  production 
is  due  to  deficiencies  of  the  soil  and  to  poor  methods  of  management. 
The  problems  of  better  farming  will  be  solved  only  when  the  investi- 
gations reveal  the  location  and  extent  of  every  kind  of  soil  in  the 
state ;  positive  information  as  to  the  extent  and  depletion  of  the  fer- 
tility; whether,  in  the  case  of  normal  soils,  limestone,  phosphorus, 
and  nitrogenous  organic  matter,  in  this  order  or  in  some  other  order, 
are  required ;  or  whether,  in  the  case  of  abnormal  soils,  some  one  essen- 
tial element  may  be  almost  entirely  lacking,  such  as  potassium  in  peaty 
soils;  in  what  cases  some  injurious  substance  must  be  removed  or 
neutralized  in  a  soil  that  may  be  rich  in  all  essentials;  and,  in  gen- 
eral, how  the  needs  of  the  soil  may  be  supplied  in  the  most  practical 
and  economical  manner  in  order  that  permanent  and  profitable  sys- 
tems of  agriculture  may  be  established. 

SOIL  PUBLICATIONS 

The  information  secured  by  the  soil  survey,  chemical  analysis, 
and  field-culture  experiments  is  disseminated  by  means  of  circulars, 
bulletins,  and  soil  reports.1  The  circulars  are  usually  concerned  with 
some  special  phase  of  soil  improvement  and  are  of  general  interest  to 
the  farmers  of  the  state.  The  bulletins  report  the  results  of  investi- 
gations upon  Illinois  soils  with  respect  to  specific  problems,  and  most 
important  of  these  is  Bulletin  323,  "The  Fertility  in  Illinois  Soils," 
which  appeared  immediately  after  the  completion  of  the  general  soil 
survey  of  the  state  in  1907.  This  publication  reports  the  stock  of 
fertility  contained  in  twenty-five  of  the  most  important  and  extensive 
types  of  soil  in  the  state,  and  the  results  of  field  experiments  pre- 
viously conducted  on  the  more  extensive  soil  types  to  ascertain  prao- 
*See  page  484  for  a  list  of  available  publications. 


10 16]  SUMMARY  OF  ILLINOIS  SOIL  INVESTIGATIONS  463 

tical  methods  of  soil  improvement.  This  information  can  be  applied 
to  more  than  half  the  soils  of  the  state. 

Soil  reports  are  published  for  each  county  after  the  detail  soil 
survey  has  been  made  and  the  essential  information  collected.  Each 
report  contains  a  colored  map  showing  the  location  and  extent  of 
every  soil  type  in  the  county,  an  invoice  of  the  total  stock  of  fertility, 
a  record  of  the  results  of  field  experiments,  a  description  in  more  or 
less  detail  of  the  essential  characteristics  of  each  soil  type,  the  inter- 
pretation of  the  data  presented,  and  an  exposition  of  the  principles 
of  soil  improvement  involved.  Such  a  publication  gives  the  reader  a 
complete  text  and  reference  book  upon  the  soils  of  the  county  con- 
cerned. Previous  to  the  preparation  of  this  bulletin,  soil  reports  had 
been  published  for  ten  counties ;  namely,  Clay,  Moultrie,  Hardin,  San- 
gamon,  LaSalle,  Knox,  McDonough,  Bond,  Lake,  and  McLean. 

The  location  of  the  first  ten  counties  for  which  soil  reports  have 
been  published  is  shown  by  Fig.  3,  page  456.  As  may  be  seen  from  the 
order  of  publication  of  the  reports  and  the  wide  distribution  of  the 
counties  over  the  state,  the  selection  has  been  made  with  a  view  to 
rendering  the  largest  benefit  to  the  great  sections  of  the  state.  Thus 
the  Clay  county  report  gives  information,  not  only  to  the  farmers  of 
Clay  county,  but  also  to  that  great  section  of  the  state,  the  wheat  belt, 
located  in  what  is  known  as  the  lower  Illinoisan  glaciation  (see  colored 
map),  for  Clay  county  is  quite  similar  to  the  other  counties  of  this 
region.  In  the  same  way  the  second  report,  Moultrie  county,  repre- 
sents the  southern  part  of  the  great  corn  belt  of  the  state,  especially 
so  far  as  it  lies  in  the  early  Wisconsin  glaciation.  The  third  report, 
Hardin  county,  represents  the  unglaciated  area  in  the  extreme  south- 
ern part  of  the  state,  etc.,  etc. 

THE  SOILS. OF  ILLINOIS 
THE  LARGE  SOIL  AREAS 

Geological  investigations  indicate  that  at  one  time  glaciers  or  ice 
sheets  covered  the  greater  portion  of  Illinois.  An  immense  amount 
of  miscellaneous  material  was  collected  and  carried  along  by  these 
glaciers,  and  large  deposits  of  boulder  clay  or  glacial  till  were  formed 
by  the  tremendous  grinding  of  accumulated  material  between  the  ice 
of  the  glaciers  and  the  surface  of  the  earth  over  which  the  glaciers 
passed.  The  drift  material  which  resulted  includes  clay,  silt,  sand, 
and  some  coarser  material  varying  in  size  from  pebbles  to  boulders. 
Wherever  the  forward  movement  of  the  glacier  just  kept  pace  with 
the  melting  of  the  ice,  a  large  amount  of  material  was  deposited,  form- 
ing moraines  or  glacial  ridges — elevations  of  various  sizes  which  now 
mark  the  boundaries  of  the  glacier  last  covering  the  territory. 
With  the  final  melting  and  disappearance  of  the  ice.  a  great  deal 


464  BULLETIN  No.  193  [December, 

of  finely  reduced  rock  material  was  scattered  and  transported  over 
other  territory  by  water  and  wind.  The  wind-blown  material,  known 
as  loess,  is  found  in  almost  all  parts  of  the  state  at  depths  varying 
from  three  feet  or  less  to  one  hundred  feet  or  more  near  the  Mississippi 
and  Illinois  rivers. 

During  the  Glacial  period,  glaciers  advanced,  receded,  and  ad- 
vanced again,  over  the  same  or  different  territory.  Thus,  at  the  end 
of  the  Glacial  period,  large  soil  areas  existed  which  now  differ  prin- 
cipally on  account  of  age.  Following  an  earlier  glaciation  known  as 
the  Kansan,  which  entered  the  state  from  the  west,  it  is  believed  that 
there  were  three  main  glaciations  in  Illinois.  The  first,  called  the 
Illinoisan,  probably  made  three  advances,  now  marked  more  or  less 
distinctly  by  terminal  moraines,  ridges,  etc.  The  oldest  of  these  ad- 
vances is  designated  as  the  lower  Illinoisan,  the  second  as  the  middle 
Illinoisan,  and  the  third  as  the  upper  Illinoisan.  In  the  same  way 
the  second  glaciation  is  now  known  as  the  pre-Ibwan  and  the  lowan, 
and  the  third  as  the  early  Wisconsin  and  the  late  Wisconsin.  The 
great  areas  covered  by  these  glaciations,  together  with  the  unglaciated 
areas,  the  areas  of  deep  loess,  the  moraines,  and  the  early  and  the  late 
bottom  and  swamp  lands,  constitute  the  fourteen  great  soil  areas  of 
Illinois,  as  may  be  seen  by  the  accompanying  map. 

INDIVIDUAL  SOIL  TYPES 

Within  these  great  soil  areas,  sixty-two  individual  soil  types  have 
been  identified  by  detail  soil  survey  in  the  first  ten  counties  for 
which  reports  have  been  published.  These  soils  are  extremely  diverse 
and  vary  considerably  with  respect  to  fertility  and  to  physical  char- 
acteristics, but  for  convenience  and  ready  comparison  they  may  be 
grouped  into  six  general  classes  as  follows: 

(1)  Upland  prairie  soils,  rich  in  organic  matter.     These  were 
originally  covered  with  wild  prairie  grasses  whose  network  of  roots 
was  protected  from  complete  decay  by  the  imperfect  aeration  resulting 
from  the  covering  of  fine  soil  material  and  the  moisture  it  contained. 
The  flat  prairie  land  is  richer  in  organic  matter  because  there  the 
grasses  and  roots  grew  more  luxuriantly  and  the  higher  moisture  con- 
tent preserved  them  still  further  from  decay.     The  upland  prairie 
soils  vary  in  topography  from  level  to  rolling,  and  include  gray  silt 
loam  on  tight  clay  of  the  lower  Illinoisan  glaciation,  which  is  the  ex- 
tensive type  in  the  wheat  belt;    brown  silt  loam,  the  most  common 
corn-belt  soil,  found  extensively  in  the  middle  and  upper  Illinoisan 
and  the  early  Wisconsin  glaciations ;  and  the  heavy  black  clay  loam, 
of  a  somewhat  swampy  nature  before  drainage,  found  in  the  very  flat 
prairies  in  the  corn-belt  glaciations. 

(2)  Upland  timber  soils,  including  those  zones   along  stream 
courses  upon  which  forests  have  grown  for  a  long  period  of  time. 


1916]  SUMMARY  OF  ILUNOIS  SOIL  INVESTIGATIONS  465 

These  soils  are  characterized  by  a  yellow,  yellowish  gray,  or  gray  color, 
which  is  due  to  their  low  organic-matter  content.  This  lack  of  or- 
ganic matter  is  the  result  of  the  long-continued  growth  of  forest  trees, 
for  as  the  forest  invaded  the  prairies  two  effects  were  produced :  the 
shading  of  the  trees  prevented  the  growth  of  the  prairie  grasses,  and 
the  trees  themselves  added  very  little  organic  matter  to  the  soil  since 
the  leaves  and  branches  either  decayed  completely  or  were  burned  by 
forest  fires.  The  timber  lands  are  divided  chiefly  into  two  classes,  the 
undulating  and  the  hilly  areas. 

(3)  Terrace  soils,  formed  on  terraces  or  benches,  in  valleys.  These 
soils  are  largely  the  result  of  the  deposition  of  material  from  over- 
loaded streams  during  the  melting  of  the  glaciers.  The  streams  of 
these  partly  filled  valleys  later  cut  thru  the  deposit  and  formed  new 
bottom  lands  or  flood  plains  at  a  lower  level,  leaving  the  old  fill  as  a 
terrace.  From  this  action,  first  and  second  bottoms  have  resulted. 

(4)  Ridge  soils,  including  those  on  morainal  ridges,  most  of 
which  have  been  forested. 

(5)  Swamp  and  bottom-land  soils,  which  include  the  flood  plains 
along  streams  and  the  peaty  swamp  areas. 

(6)  Residual  soils,  formed  by  the  accumulation  of  loose  material 
resulting  from  the  weathering  of  rocks  in  place.    Very  little  of  this 
class  of  soils  exists  in  Illinois  owing  to  the  action  of  the  glaciers  in 
removing  the  residual  material  and  covering  it  with  glacial  drift. 

FERTILITY  INVOICE 

The  fertility  invoice  of  the  more  extensive  soil  types  of  the  state — 
those  occupying  5  percent  or  more  of  a  county — is  given  in  Table  1. 
The  results  reported  are  as  a  rule  averages  of  many  analyses,  which 
like  most  things  in  nature  show  more  or  less  variation,  but  for  all 
practical  purposes  these  averages  are  most  trustworthy  and  sufficient. 

In  studying  this  table,  it  will  be  well  to  keep  in  mind  that  the 
most  productive  soils  of  normal  physical  composition  contain  in  the 
surface  soil  of  an  acre  about  8,000  pounds  of  total  nitrogen,  2,000 
pounds  of  total  phosphorus,  and  more  than  30,000  pounds  of  total 
potassium.  It  will  be  noted  here  that  some  soils  are  extremely  poor  in 
the  essential  elements  of  fertility,  while  others  are  abundantly  sup- 
plied. From  the  standpoint  of  the  productive  power  of  soils,  nitrogen 
and  phosphorus  are  the  most  extensively  deficient  elements  of  plant 
food.  Nitrogen  varies  from  about  900  pounds  per  acre  in  yellow  silt 
loam  to  over  8,000  pounds  in  black  clay  loam  and  about  33,000  pounds 
in  peat.  Phosphorus  varies  from  about  600  pounds  per  acre  in  some 
of  the  upland  timber  soils  to  2,000  pounds  in  some  of  the  upland 
prairie  soils. 

Figured  on  the  basis  of  100  bushels  of  corn  per  acre,  the  grain 
only  being  removed,  the  common  corn-belt  prairie  land  contains  in 


466 


BULLETIN  No.  193 


[December, 


'3  'r3    BJ 

co  -3  g 

cS   O< 

4J 

r-,      £ 

00 

01 

A 

«     B 

J        -S 

•H 

Total 
magne- 
sium 

of 

111 

5  ^ 

H  §,« 

-3       +3 

J      3 

03 

H     O 

C6    93     ^ 

3  ;§, 

H^-2 

r. 

ft 

^    75 

U     0 

H        CO 

H              qj 

.     t> 

H 

IP 

CO 

'o 

H        3 

^  "3  o 

OQ 

.2 
'C 

^     ° 

-P    tnj  (- 

'3 

« 

2  'a 

o  ^ 

PH 

§      3 

^ 

a 
.2 

r2 

^    a 
3  -2 

2 

"E, 
P 

'3 

cS 

3  1 

'So 

M      ,-g 

h 

O 

3  .S 

^ 

H        <v, 

a    S 

CO 
b 

4    <y 

H      ^ 

(H 
.      ® 

'o 
CO 

2   fl 

H      0 

& 

(P 

hr 

a1 

o> 

h 

« 

(X 

> 

l\* 

<1 

_ 

"S 

CO 

(     ^J       . 

.-H         p     .     O 

jO  -*j 

'mOO 
2;  rH  rH 
• 

H 


(M  O 


ooeof-io       i—  i  os  --^ 

(MOit^CC         COO5<MO-)<M 
OS  »H  i-l  «          TflOiHtOOO 


OOQOO  OOOOO 
OQ  i—  1  t-~  CO  (MI>.i-HTti^ 
COO5COO5  i—  1  OO  (M  O  t- 


(MCOCOCOCO 


IOOOOO 


oqinoowec 


^S 
1—  1  r* 


C  §.      R   R 
B        IB  <Q  oj  cd  4 

S3      .2  'o  g  .22  .2 

l    lilll 


m 


w 


cc 


omooooooiooioo 

iM 
1C 


(M(M(M(M(M 


- 

.2  'S  .2  'S  •  .2  '3  .2  g  'S  • 


02 


B 


IO  O  O  O  O 
O3  CO  OS  M  ?O 
5D  -*1  O3  CO 

OJ  00  •*  o  5O 


>o  in  o  o  o 

•*  rH  OS  >O 
t~  O  IM  •*  IO 


»O  LO  O  O  O 
«O  CO  O  •*  rt* 
OJ  CO  OS  rH  O 


cS  g 
" 


m  LIBRARY 

OF  THE 
UNIVERSITY  OF  ILLINOIS 


II II 


o  a 

Eg 


cl 

II 

og 


£8 


^•^^                  ^l^~ 

I 

M 
fl. 

c 
• 

E 
2 

B 
0 

c 
o 

1 

JD 

01 

.2 

•o 

T3 

«J 

a 

S 

of 

bO 

te 

E 
2 

O. 

£ 

c 

0 

c 
o 

o 

I 

£ 

1 

I 

« 

>* 

o> 

T3 

« 

3 

-o 
0 

1 

B000 


i — i 


0101 


1916]  SUMMARY  OF  ILLINOIS  SOIL  INVESTIGATIONS  467 

the  surface  about  enough  nitrogen  for  48  crops  and  sufficient  phos- 
phorus for  70  crops.  On  the  other  hand,  it  contains  enough  potassium 
to  produce  1,790  such  crops;  and  with  good  methods  of  farming, 
potassium  may  be  renewed  rapidly  enough  from  the  subsoil,  by  un- 
avoidable surface  washing,  to  maintain  the  potassium  content  of  the 
soil  indefinitely.  If  production  is  to  be  maintained,  it  will  be  neces- 
sary, therefore,  to  supplement  the  supply  of  nitrogen  and  phosphorus 
in  these  soils.  The  necessity  for  the  use  of  organic  matter  is  indicated 
by  the  ratio  of  nitrogen  to  organic  carbon.  A  narrow  ratio  exists 
where  the  organic-matter  content  is  low,  and  a  wide  one  where  there 
is  sufficient  of  this  material  present. 

Measured  by  actual  crop  requirements,  some  of  these  soils  show 
a  deficiency  in  the  elements  calcium  and  magnesium.  Limestone, 
therefore,  in  addition  to  correcting  soil  acidity,  may  have  considerable 
value  for  the  calcium  and  magnesium  which  it  contains. 

While  the  amount  of  plant  food  contained  in  the  subsurface  and 
subsoil  strata  is  of  interest,  no  analyses  for  these  strata  are  reported 
here.  The  chief  thing  of  importance  in  systems  of  permanent,  profit- 
able agriculture  is  the  maintenance  of  a  good  surface  soil,  for  even  a 
rich  subsoil  is  of  but  little  value  if  it  lies  beneath  a  worn-out  surface. 
For  detailed  discussion  of  the  fertility  in  Illinois  soils  below  the  seven- 
inch  depth,  the  reader  is  referred  to  the  various  soil  reports  issued  by 
this  station  and  to  Bulletin  123. 

RESULTS  OF  FIELD-CULTURE  EXPERIMENTS 

The  field-culture  experiments  planned  in  connection  with  the  in- 
formation furnished  by  the  soil  survey  and  soil  analysis  have  demon- 
strated that  it  is  possible  to  practice  a  system  of  farming  that  is  both 
permanent  and  profitable.  A  summary  of  the  results  secured  upon  a 
number  of  the  most  important  soil  types  in  the  different  soil  areas, 
showing  the  effect  and  value  of  various  forms  of  soil  treatment,  is 
presented  upon  the  following  pages.  The  data  are  arranged  by  soil 
types,  which  are  presented  according  to  age  when  occurring  in  more 
than  one  soil  area. 

Since  a  definite  system  of  farming  may  or  may  not  be  profitable, 
depending  upon  the  price  received  for  produce,  the  field  results  are 
usually  summarized  in  two  sets  of  money  values  to  emphasize  this  fact. 
Low  prices  are  used  to  represent  the  value  of  the  produce  in  the  field, 
and  high  prices  to  represent  the  market  value.  The  prices  used  are 
as  follows :  corn,  35  and  50  cents  per  bushel ;  oats,  28  and  40  cents ; 
wheat  70  cents  and  $1 ;  soybeans,  70  cents  and  $1  per  bushel.  Meas- 
ured by  average  Illinois  prices  for  the  past  ten  years,  the  lower  values 
are  not  too  high  for  crops  standing  in  the  field  ready  for  harvest.  Un- 
less otherwise  specified,  these  are  the  values  used  in  the  following 
discussion. 


468  BULLETIN  No.  193  [December, 

UPLAND  PRAIRIE  SOILS 
Black  Clay  Loam  of  Early  Wisconsin  Glaciation  (1120) 

Urbana  Field. — At  Urbana,  on  the  South  Farm  of  the  University 
of  Illinois,  a  series  of  plots  devoted  primarily  to  crop-production  ex- 
periments extends  across  an  area  of  black  clay  loam.  A  four-year 
rotation  of  wheat,  corn,  oats,  and  clover  (or  soybeans)  is  practiced. 
Where  rock  phosphate  has  been  applied  at  the  rate  of  500  pounds  an 
acre  per  annum  in  connection  with  crop  residues  in  the  grain  system, 
the  value  of  the  increase  per  ton  of  phosphate  has  been  as  follows,  in 
three  successive  rotations: 

Lower  prices       Higher  prices 

First  rotation $2.13  $3.04 

Second  rotation 4.70  6.71 

Third  rotation 6.48  9.26 

In  the  live-stock  system,  the  phosphorus  naturally  supplied  with 
the  manure,  supplemented  by  that  liberated  from  this  fertile  soil,  has 
been  approximately  sufficient  to  meet  the  crop  requirements.  The 
value  of  the  increase  per  ton  of  phosphate,  as  an  average  of  the  twelve 
years,  has  been  only  $2.26  at  the  lower  prices  and  $3.26  at  the  higher 
prices.  These  returns  are  less  than  half  the  cost  of  the  phosphorus 
applied,  and  in  some  seasons  no  benefit  has  appeared. 

Brown  Silt  Loam  of  Middle  Illinoisan  Glaciation  (426) 

Virginia  Field. — At  Virginia,  in  Cass  county,  the  University  es- 
tablished an  experiment  field  in  1902  upon  brown  silt  loam  somewhat 
above  the  average  in  productive  power.  A  three-year  rotation  was 
begun  on  three  different  series  of  plots.  Corn,  oats,  and  cowpeas  were 
grown  the  first  six  years,  after  which  the  rotation  was  changed  to 
corn,  oats,  and  clover. 

During  the  first  seven  years  (1902  to  1908),  phosphorus  applied 
at  the  rate  of  25  pounds  per  acre  per  annum  in  the  form  of  steamed 
bone  meal  produced  an  increase  of  6.8  bushels  of  corn,  .4  bushel  of 
oats,  .04  ton  of  hay.  During  the  next  three  years  (1909  to  1911),  the 
increases  were  10.5  bushels  of  corn,  13.1  bushels  of  oats,  and  .69  ton 
of  hay.  These  results  were  to  be  expected,  for  the  chemical  analysis 
of  the  soil  shows  that  phosphorus  is  not  abundant  and  that  nitrogen 
is  the  first  limiting  element.  Thus  phosphorus  could  show  no  marked 
effect  until  nitrogen  was  gradually  increased  by  the  use  of  legume 
crops  and  farm  manure. 

On  another  series,  commercial  nitrogen  was  applied  in  a  four- 
year  rotation  of  corn,  corn,  oats,  and  wheat,  thus  giving  an  opportunity 
to  compare  this  form  of  nitrogen  to  that  supplied  the  soil  by  grain 
and  live-stock  farming.  On  plots  treated  alike  with  respect  to  lime 
and  phosphorus,  legumes  in  rotation  and  some  crop  residues  plowed 


1916]  SUMMARY  OF  ILLINOIS  SOIL  INVESTIGATIONS  469 

under  increased  the  six-year  average  yield  of  corn  by  24.2  bushels, 
and  farm  manure  and  legumes  increased  the  yield  by  26.6  bushels; 
while  100  pounds  of  commercial  nitrogen  in  about  800  pounds  of 
dried  blood,  costing  $15  to  $20  per  annum,  increased  the  yield  only 
19.5  bushels. 

The  two  important  lessons  from  the  Virginia  field  are :  first,  when 
nitrogen  is  the  limiting  element,  nothing  else  can  take  its  place,  and, 
even  tho  phosphorus  may  be  deficient,  its  addition  will  not  produce 
marked  results  until  sufficient  nitrogen  is  provided ;  second,  the  grow- 
ing of  legumes  in  rotation  and  the  use  of  crop  residues  or  farm  manure 
may  produce  even  better  results  than  high-priced  commercial  nitrogen. 
(For  further  details  see  Soil  Eeport  No.  4,  Sangamon  county.) 

Brown  SUt  Loam  of  Upper  Illinoisan  Glaciation  (526) 

Galesburg  Field. — Upon  the  experiment  field  located  near  Gales- 
burg  on  brown  silt  loam  prairie  soil,  a  six-year  rotation  of  corn,  corn, 
oats,  clover,  wheat,  and  clover  has  been  practiced.  There  are  only 
three  independent  series  of  plots,  so  that  while  corn  is  grown  every 
year,  the  other  crops  are  harvested  every  other  year,  with  the  excep- 
tion of  clover,  which  should  be  on  the  field  every  year  either  as  a 
regular  crop  or  in  the  stubble  of  oats  and  wheat. 

The  twenty  plots  of  each  series  are  so  treated  that  the  value  of 
additions,  consisting  of  phosphorus  in  the  form  of  rock  phosphate, 
potassium,  and  limestone,  may  be  known  in  both  live-stock  and  grain 
farming  (see  page  461).  On  Plot  19  of  the  three  series,  commercial, 
nitrogen  at  the  rate  of  25  pounds  an  acre  per  annum  is  used  in  addi- 
tion to  the  regular  treatment. 

Three  facts  are  clearly  brought  cut  by  the  data  from  this  field : 

First. — Commercial  nitrogen  at  15  cents  a  pound  has  never  paid 
its  cost.  As  the  system  of  providing  "home-grown"  nitrogen  has 
developed,  the  effect  of  commercial  nitrogen  has  decreased,  and  as  an 
average  of  the  five  years  1908-1912  it  paid  back  only  4  percent  of  its 
annual  cost. 

Second. — Potassium,  likewise,  has  never  paid  its  cost ;  but  during 
the  early  years,  with  no  adequate  provision  for  decaying  organic 
matter,  the  soluble  potassium  salts  produced  marked  effect,  owing  no 
doubt  in  part  to  their  power  to  make  available  the  raw  phosphate  rock 
applied  with  the  potassium.  With  the  increase  of  organic  matter,  the 
effect  of  the  potassium  has  been  greatly  reduced.  As  an  average  of 
the  six  years  from  1907  to  1912,  potassium  costing  $7.50  paid  back 
only  $1. 

Third. — Fine-ground  rock  phosphate  applied  at  the  rate  of  500 
pounds  an  acre  per  annum  in  connection  with  decaying  organic  matter 
has  paid  back  the  following  increases  in  crop  values  per  ton  of  phos- 
phate applied: 


470 


BULLETIN  fto.  193 


[December, 


Lower  prices  Higher  prices 

Average  1904   and   1905 $3.53  $5.04 

Average  1906-1908    7.73  11.04 

Average  1909-1911 8.60  12.29 

Average  1912-1914 12.93  18.49 

These  increases  have  been  realized  by  the  removal  from  the  soil  of 
only  one-third  of  the  phosphorus  applied,  leaving  two-thirds  in  the 
soil  as  positive  enrichment.  (See  Soil  Report  No.  6,  Knox  county, 
for  detailed  data  on  crop  yields,  etc.) 

Brown  Silt  Loam  of  Early  Wisconsin  Glaciation  (1126) 

Sibley  Field. — The  Sibley  experiment  field,  located  in  Ford 
county  upon  typical  brown  silt  loam  prairie  soil,  was  cropped  previous 
to  1902  with  corn  and  oats  under  a  tenant  system  which  had  caused 
the  active  organic-matter  content  to  be  somewhat  deficient.  One  series 
of  plots  treated  in  such  a  manner  as  to  bring  out  facts  concerning  the 
needs  of  the  soil,  in  which  phosphorus  is  the  limiting  element,  has 
furnished  some  interesting  information. 

In  1903  the  addition  of  phosphorus  produced  an  increase  of  8 
bushels  of  corn,  nitrogen  produced  no  increase,  but  nitrogen  and  phos- 
phorus combined  increased  the  yield  by  15  bushels.  After  six  years 
of  additional  cropping,  nitrogen  appeared  to  become  the  most  limiting 
element,  the  increase  in  corn  in  1907  being  9  bushels  from  nitrogen 
and  only  5  bushels  from  phosphorus,  while  nitrogen  and  phosphorus 
together  produced  an  increase  of  33  bushels.  Thus  even  tho  phos- 
phorus was  a  limiting  element,  the  nitrogen  becoming  available  an- 

TABLE  2. — VALUE  OF  CROPS  PER  ACRE  IN  TWELVE  YEARS,  SIBLEY  FIELD 

1902  TO  1913 


Plot 

Soil  treatment  applied 

Total  value  of  12  crops 

Lower 
prices 

Higher 
prices 

101 
102 

None     .  .        .  .              

$172.89 
186.51 

$246.98 
266.45 

Lime  

103 
104 
105 

Lime    nitrogen                                                       .          .... 

177.44 
217.78 
167.32 

253.49 
311.11 

239.03 

Lime    phosphorus                                                     

Lime,  potassium  

106 
107 
108 

Lime    nitrogen     phosphorus             

246.91 
198.16 
204.90 

352,73 
283.08 
292.71 

Lime    nitro°°en    potassium                      

Lime,  phosphorus,  potassium  

109 
110 

257.91 
242.47 

368.45 
346.38 

Nitrogen,  phosphorus,  potassium  

Value  of  Increase  per  Acre  in  Twelve  Years 


For  nitrogen 

For  phosphorus '. 

For  nitrogen  and  phosphorus  over  phosphorus 

For  phosphorus  and  nitrogen  over  nitrogen 

For  potassium,  nitrogen,  and  phosphorus  over  nitrogen 
and  phosphorus 


$-9.07 
31.27 
29.13 
69.47 

11.00 


$-12.96 
44.66 
41.62 
99.24 


1916] 


SUMMARY  OF  ILLINOIS  SOIL  INVESTIGATIONS 


471 


nually  was  but  little  in  excess  of  the  phosphorus.  The  untreated  land 
apparently  became  less  productive,  whereas  on  land  receiving  both 
nitrogen  and  phosphorus  the  yields  were  appreciably  increased,  so 
that  in  1907  the  untreated  rotated  land  produced  only  34  bushels  of 
corn  and  the  land  treated  with  lime,  nitrogen,  and  phosphorus  yielded 
72  bushels  per  acre  (more  than  twice  as  much),  altho  both  plots  pro- 
duced the  same  yield  (57.3  bushels)  in  1902.  The  total  values  per 
acre  of  the  twelve  crops  for  each  plot  are  shown  in  Table  2. 

Here  it  is  seen  that  with  the  lower  prices  phosphorus  without 
nitrogen  produced  $31.27  in  addition  to  the  increase  by  lime,  but  that 
with  nitrogen  it  produced  $69.47  above  the  crop  values  where  only 
lime  and  nitrogen  have  been  used.  The  results  show  that  in  26  cases 
out  of  48  the  addition  of  potassium  decreased  crop  yields.  Lime  pro- 
duced an  average  increase  of  $14.53,  or  $1.21  an  acre  per  year;  which 
shows  that  the  time  has  come  when  limestone  must  be  applied  to  some 
of  the  brown  silt  loam  soils.  (Detailed  data  in  regard  to  crop  yields 
will  be  found  in  Soil  Report  No.  10,  McLean  county.) 

Bloomington  Field. — The  results  of  thirteen  years'  work  on  the 
experiment  field  located  near  Bloomington  on  brown  silt  loam  prairie 
soil  are  much  the  same  as  those  from  the  Sibley  field,  as  may  be  seen 
from  Table  3. 

The  treatment  of  this  field  differs  from  that  at  Sibley  in  that  in 
1905  the  use  of  commercial  nitrogen  was  discontinued,  clover  wras 
introduced  into  the  rotation,  and  crop  residues  Avere  subsequently  re- 
turned to  the  soil.  "With  this  method,  phosphorus  has  produced  even 

TABLE  3. — VALUE  OP  CROPS  PER  ACRE  IN  THIRTEEN  YEARS,  BLOOMINGTON  FIELD 

1902  TO  1914 


Plot 

Soil  treatment  applied 

Total  value  of  13  crops 

Lower 
prices 

Higher 
prices 

101 

102 

None  

$186.83 
186.76 

$260.90 
266.80 

Lime  

103 
104 
105 

Lime,  residues  

193.83 
286.61 
190.53 

276.90 
409.45 
272.19 

Lime,  phosphorus  

Lime,  potassium  

106 
107 
108 

Lime,  residues,  phosphorus  

285.03 
191.10 
294.91 

407.19 
273.00 
421.31 

Lime,  residues,  potassium  
Lime,  phosphorus,  potassium  

109 
110 

Lime,  residues,  phosphorus    potassium                

284.47 
259.10 

406.39 
370.15 

Residues,  phosphorus,  potassium.  . 

Value  of  Increase  per  Acre  in  Thirteen  Years 


For    residues 

For  phosphorus 

For  residues  and  phosphorus  over  phosphorus 

For  phosphorus  and  residues  over  residues 

For  potassium,  residues,   and   phosphorus   over   residues 
and  phosphorus 


$  7.07 
99.85 
-1.58 
91.20 


$  10.10 

142.65 

-2.26 

130.29 

-.80 


472 


BULLETIN  No.  193 


[December, 


larger  increases  ($99.85)  than  have  been  produced  by  phosphorus  and 
nitrogen  over  nitrogen  on  the  Sibley  field  ($69.47).  The  average 
yearly  increase  due  to  phosphorus  in  connection  with  the  use  of  legume 

TABLE  4. — YIELDS  PER  ACRE,  THREE- YEAR  AVERAGES,  URBANA  FIELD 
First  Eotation:     1902-1904 


Serial 
plot 
No. 

Soil  treatment 

Corn 
bu. 

Oats 
bu. 

Hay 

tons 

Value  of  3  crops 

Lower 
prices 

Higher 
prices 

1 

2 
3 

4 
5 

None  

75.4 
77.4 
75.3 

78.4 
80.8 

48.8 
45.1 
50.4 
47.3 
58.2 

.49 
.44 
.41 
.42 
.44 

$43.48 
42.80 
43.33 
43.62 
47.66 

$62.12 
61.14 
61.91 
62.32 
68.08 

Legume  cover  crop  

None  

Legume  cover  crop,  lime  

Lime   

6 
7 
8 

9 
10 

Legume  cover  crop,  lime,  phosphorus  

88.0 
88.8 

90.1 

90.5 
86.5 

52.5 
56.6 

48.3 
54.3 
53.2 

.50 
.98 

.64 
1.34 
1.23 

49.00 
53.79 

49.53 
56.26 
53.78 

70.00 
76.84 

70.77 
80.37 
76.83 

Lime,  phosphorus    

Legume  cover  crop,  lime,  phosphorus, 
potassium    

Lime,  phosphorus,  potassium  

Lime,  ohosohorus.  t»otassium  .  . 

Second  Eotation:    1905-1907 


Serial 
plot 
No. 

Soil  treatment 

Corn 
bu. 

Oats 

1>u. 

Clover 
tons 

Value  of  3  crops 

Lower 
prices 

Higher 
prices 

1 

2 
3 
4 
5 

None  

71.5 
68.5 
80.5 
72.3 

84.8 

46.6 
52.0 
54.8 
58.6 
59.8 

2.07 
1.83 
2.19- 
1.98 
2.46 

$52.56 
51.34 
58.84 
55.57 
63.64 

$75.09 
73.35 
84.07- 
79.39 
90.92 

Legume  cover  crop   

Manure  

Legume  cover  crop   lime  

Manure,  lime  

6 
7 
8 

9 
10 

Legume  cover  crop,  lime,  phosphorus  

90.4 
93.2 

93.8 
95.6 
901 

70.7 
71.6 

71.7 
66.9 
6!?  9 

2.69 
3.47 

3.06 
3.73 
2.86 

70.26 
76.96 

74.32 
78.30 
69.17 

100.38 
109.94 

106.18 
111.86 
98.81 

Manure,  lime,  phosphorus  

Legume  cover  crop,  lime,  phosphorus, 
potassium  

Manure,  lime,  phosphorus,  potassium  .... 
Manure  (*}.  lime.  DnosDhorus  (  x^  .  . 

Third  Rotation:    1908-1910 


Serial 
plot 
No. 

Soil  treatment 

Corn 
bu. 

Oats 
bu. 

Clover 
tons 
(bu.) 

Value  of  3  crops 

Lower 

prices 

Higher 
prices 

1 

2 
3 
4 
5 

None             

49.4 
51.5 
69.3 
58.1 
74.9 

40.8 
43.4 
46.2 
45.7 
47.5 

2.30 
(1.93) 
2.53 
(2.02) 
2.94 

$44.81 
43.69 
54.90 
47.27 
60.09 

$64.02 
62.41 
78.43 
67.53 
85.85 

Residues  .                   

Manure     

Residues,  lime   

Manure,  lime   

6 
7 
8 
9 
10 

Residues    lime    phosphorus  

83.8 
86.6 
86.7 
90.9 
81.3 

54.5 
55.4 
53.5 
53.6 
54.3 

(2.64) 
4.17 
(1.99) 
3.90 
3.79 

63.07 
75.01 
59.26 
74.12 
70.19 

90.10 
107.16 
84.65 
105.89 
100.27 

Manure,  lime,  phosphorus  

Residues,  lime,  phosphorus,  potassium  .  .  . 
Manure,  lime,  phosphorus,  potassium  .... 
Manure  (x),  lime,  phosphorus  (x)  

X— extra    heavy    applications    of    manure    and    phosphorus;    residties=:corn 
stalks,  straw  of  wheat  and  oats,  and  all  legumes  except  seed. 


1916] 


SUMMARY  OF  ILLINOIS  SOIL  INVESTIGATIONS 


473 


TABLE  5.— YIELDS  PER  ACRE,  FOUR-YEAR  AVERAGES,  URBANA  FIELD 
1911  TO  1914 


Serial 
plot 
No. 

Son 

treat- 
ment 

Wheat 

In. 

Corn 
Zm. 

Oats 
2m. 

Soybeans-3 
tons  (bu.~) 

Clover-1 
tons  (6«.) 

Alfalfa 
tons 

Value  o 

Lower 
prices 

£  5  crops 

Higher 
prices 

1 

2 
3 
4 
5 

0  

18.3 
19.7 
20.3 
22.3 
24.9 

50.8 
53.8 
59.3 
55.7 
58.6 

39.8 
40.6 
48.8 
42.8 
51.6 

1.60 
(20.1) 
1.60 
(19.0) 
1.66 

1.70 
(  .74) 
1.43 
(1.03) 
1.94 

1.70 
1.27 
1.13 
1.19 
1.67 

$65.00 
64.72 
:  67.44 
67.20 
76.19 

$92.87 
92.47 
96.35 
96.00 
108.84 

R  

M  

RL.  .  .  . 
ML  

6 
7 
8 
9 
10 

RLP... 
MLP... 
RLPK. 
MLPK. 
MxLP*. 

37.4 
36.6 
36.1 
35.3 
43.5 

62.2 
63.8 
58.9 
59.6 
55.7 

58.7 
60.9 
59.1 
65.1 
67.2 

(21.0) 
1.88 
(22.2) 
2.09 
2.14 

(2.48) 
2.90 
(1.41) 
2.72 
2.94 

2.69 
2.63 
2.58 
2.66 
2.84 

98.58 
98.36 
94,61 
98.15 
105.02 

140.83 
140.51 
135.16 
140.22 
150.03 

Lezulegume  cover  crop;  L=lime;  Pz=phosphorus ;  M=manure;  x— extra 
heavy  applications  of  manure  and  phosphorus;  R=crop  residues  (corn  stalks, 
straw  of  wheat  and  oats,  and  all  legumes  except  seed  and  alfalfa  hay). 

crops  or  nitrogen  has  been  $7.02  an  acre,  which  is  $4.52  above  the  cost 
of  phosphorus  in  200  pounds  of  steamed  bone  meal,  the  form  in  which 
it  is  applied.  The  total  phosphorus  applied  from  1902  to  1914,  as  an 
average  of  all  plots  where  it  has  been  used,  has  amounted  to  325 
pounds  per  acre  and  has  cost  $32.50.  This  has  paid  back  $97.20,  or 
300  percent  on  the  investment.  Potassium,  on  the  other  hand,  has 
paid  back  less  than  7  percent  of  its  cost  in  the  thirteen  years.  (De- 
tailed data  in  regard  to  crop  yields  will  be  found  in  Soil  Report  No. 
10,  McLean  county.) 

Urbana  Field. — On  the  University  North  Farm  at  Urbana,  on  the' 
common  brown  silt  loam  prairie  soil,  a  rotation  of  corn,  oats,  and 
clover  was  practiced  for  nine  years  (1902  to  1910),  which  has  been 
followed  by  a  combination  rotation  involving  corn,  oats,  clover,  wheat, 
and  alfalfa.  The  various  plots  upon  each  series  are  so  treated  as  to 
show  the  value  of  various  additions  in  both  live-stock  and  grain  farm- 
ing. On  all  series,  Plot  10  is  treated  with  about  five  times  as  much 
manure  and  phosphorus  as  is  applied  on  the  other  plots,  in  order  to 
remove  the  limitations  of  inadequate  fertility  and  thus  to  determine 
the  climatic  possibilities  of  crop  yields.  Tables  4  and  5  give  the  three- 
year  and  the  four-year  averages,  respectively,  of  crop  yields  and  the 
value  of  the  crops  by  rotations,  with  both  the  higher  and  the  lower 
prices.  No  detailed  discussion  of  this  interesting  data  will  be  given 
here  (see  Soil  Report  No.  9,  Lake  county,  or  No.  10,  McLean  county), 
but  a  few  points  of  interest  will  be  indicated  for  further  study. 

While  seasonal  variations  are  inevitable,  a  comparison  of  crop 
yields  by  rotations,  with  and  without  soil  treatment,  is  instructive. 
On  the  untreated  land  distinctly  higher  average  yields  of  corn  appear 
in  the  first  rotation  than  in  succeeding  rotations,  as  75.4  bushels  in  the 
first  and  49.4  bushels  in  the  last  of  the  three-year  rotations.  The 


474 


BULLETIN  No.  193 


difference  in  yields  of  corn  between  treated  and  untreated  land  be- 
comes greater  with  succeeding  rotations,  as  is  seen  by  the  difference 
of  13.4  bushels  between  Plots  1  and  7  in  the  first  rotation,  and  of  37.2 
bushels  between  the  same  plots  in  the  last  of  the  three-year  rotations. 
Such  evidence  points  to  the  fact  that  fertility  cannot  be  maintained 
by  rotation  alone,  but  that  with  a  good  system  of  soil  treatment  maxi- 
mum production  may  be  expected  indefinitely. 

Attention  is  also  called  to  the  striking  effects  of  soil  treatment 
upon  the  wheat  yields,  which  show  100  percent  increase,  as  an  average, 
during  the  four-year  rotation.  At  the  lower  prices  for  produce,  farm 
manure  has  been  worth  84  cents  per  ton  during  the  ten  years  it  has 
been  used  on  Plot  3. 

As  a  general  average,  the  plots  receiving  limestone  have  produced 
$1.22  an  acre  a  year  more  than  the  plots  not  receiving  limestone,  and 
this  corresponds  to  more  than  $6  a  ton  for  all  the  limestone  applied ; 


FIG.  6. — METHOD  OF  SCATTERING  LIMES 


PHOSPHORUS1 


but  the  amounts  of  limestone  applied  before  1911  were  so  small  and 
the  results  so  variable  that  final  conclusions  cannot  be  drawn  until 
further  data  are  secured.  However,  since  all  comparisons  of  rotation 
periods  show  some  increase,  the  need  of  limestone  for  the  best  results 
and  the  highest  profits  seems  well  established. 

Potassium  applied  at  an  estimated  cost  of  $2.50  an  acre  a  year 
seemed  to  produce  slight  increases,  on  the  average,  during  the  first 
and  second  rotations,  but  the  net  result  thru  the  1914  yields  was  an 
'For  description  of  this  machine,  see  page  16  of  Circular  110  of  this  station. 


1916]  SUMMARY  OF  ILLINOIS  SOIL  INVESTIGATIONS  475 

average  loss  of  $2.53  per  acre  per  annum,  including  the  cost  of  the 
potassium. 

The  annual  application  of  25  pounds  of  phosphorus  in  200  pounds 
of  steamed  bone  meal  valued  at  $28  per  ton,  or  of  75  pounds  in  600 
pounds  of  rock  phosphate  valued  at  $7  per  ton,  in  connection  with 
decaying  organic  manures,  has,  as  an  average  for  each  dollar  invested 
in  phosphorus,  paid  as  follows : 

Lower  prices      Higher  prices 

First    rotation,   1902-1904 $     ,69  $     .99 

Second  rotation,  1905-1907 1.67  2.39 

Third  rotation,  1908-1910 2.09  2.99 

Fourth    rotation,   1911-1914 2.19  3.13 

The  excessive  applications  on  Plot  10  have  usually  produced  rank 
growth  of  straw  and  stalk,  with  the  result  that  oats  have  often  lodged 
badly  and  corn  has  frequently  suffered  from  drouth  and  has  eared 
poorly.  Wheat,  however,  as  an  average,  has  yielded  best  on  this  plot. 
The  largest  yield  of  corn  was  118  bushels  per  acre  in  1907. 

On  the  University  South  Farm  at  Urbana,  on  typical  brown  silt 
loam  prairie,  where  one  ton  per  acre  of  rock  phosphate  is  applied 
every  four  years  in  connection  with  organic  manures  for  a  rotation 
of  corn,  oats,  clover,  and  wheat,  applications  of  fine-ground  rock  phos- 
phate have  paid  as  follows  in  the  value  of  the  increase  produced : 

PER  TON  OF  PHOSPHATE        PER  $1  INVESTED 

Lower         Higher             Lower  Higher 

prices           prices              prices  prices 

First  rotation,  1903-1906 $8.26           $11.80  $1.18  $1.69 

Second  rotation,  1907-1910 11.33             16.19               1.62  2.31 

Third  rotation,  1911-1914 18.89             26.98               2.70  3.85 

The  comparative  values  of  the  increases  from  rock  phosphate  and 
limestone,  as  an  average  of  the  four-year  rotation  1911-1914,  in  both 
live-stock  and  grain  farming,  are  as  follows: 

EESIDUE  SYSTEM  LIVE-STOCK  SYSTEM 

Lower         Higher  Lower         Higher 
prices          prices  prices          prices 

Gain  for  phosphorus $18.80  $26.86  $18.96  $27.09 

Gain  for  limestone 2.30  3.29  2.54  3.63 

Brown-Gray  Silt  Loam  on  Tight  Clay  of  Middle  Illinoisan 
Glaciation  (428) 

Mascoutan  Field. — Table  6,  showing  the  value  of  twelve  crops 
from  the  Mascoutah  experiment  field  located  upon  brown-gray  silt 
loam  on  tight  clay  of  the  middle  Illinoisan  glaciation,  are  given  here 
since  there  is  no  data  for  this  type  in  either  the  lower  or  the  upper 
Illinoisan  glaciation.  In  order  to  secure  information  as  quickly  as 
possible,  commercial  plant  foods  in  readily  available  form  were  ap- 
plied in  a  four-year  rotation  of  corn,  corn,  oats,  and  wheat. 


476 


BULLETIN  No.  193 


[December, 


TABLE  6. — VALUE  OF  CROPS  PER  ACRE  IN  TWELVE  YEARS,  MASCOUTAH  FIELD 

1902  TO  1913 


Plot 

Soil  treatment  applied 

Total  value  of  12  crops 

Lower 
prices 

Higher 
prices 

501 
502 

None   

$90.07 
90.47 

$128.67 
129.24 

Lime   

503 
504 
505 

Lime,  nitrogen  

134.46 
106.10 
100.96 

192.08 
151.57 
144.23 

Lime,  phosphorus   

Lime,  potassium    

506 
507 
508 

Lime,  nitrogen,  phosphorus  

190.55 
205.60 
123.84 

272.21 
293.72 
176.92 

Lime,  nitrogen,  potassium  

Lime,  phosphorus,  potassium   

509 
510 

Lime,  nitrogen,  phosphorus,  potassium  

190.67 
177.58 

272.39 
253.69 

Nitrosren.  phosphorus,  potassium  . 

Value  of  Increase  per  Acre  in  Twelve  Years 


For  nitrogen 

For  phosphorus  

For  nitrogen  and  phosphorus  over  phosphorus 

For  phosphorus  and  nitrogen  over  nitrogen 

For  potassium,   nitrogen,    and   phosphorus   over   nitrogen 
and   phosphorus 


$43.99 
15.63 
84.45 
56.09 

.12 


$62.84 
22.33 

120.64 
80.13 

.18 


Nitrogen  is  clearly  the  element  of  greatest  benefit  upon  this  soil 
type,  as  shown  by  the  fact  that  in  twelve  years  the  dried  blood  in- 
creased the  crop  values,  at  the  lower  prices,  from  $90.47  to  $134.46, 
a  gain  of  $43.99.  In  comparison,  phosphorus  produced  an  increase 
valued  at  $15.63  and  potassium  an  increase  of  only  $10.49,  when  used 
singly.  In  considering  these  three  elements,  starting  with  $90.47 
(Plot  2),  the  increases  per  acre  in  crop  values  were  as  follows: 

For  nitrogen  over  lime $  43.99 

For  phosphorus  as  a  further  addition 56.09 

For  potassium  as  a  final  addition .12 

For  total  increase $100.20 

This  demonstration  of  doubling  crop  values  is  highly  important, 
for  it  shows  the  possibilities  of  soil  treatment.  From  the  composition 
of  the  soil  it  is  clear  that  both  nitrogen  and  phosphorus  must  be  sup- 
plied for  a  permanent  system  of  farming,  altho  there  may  be  some 
question  as  to  which  of  the  two  is  most  needed.  Commercial  nitrogen, 
altho  producing  marked  gains,  never  paid  its  cost;  and  while  phos- 
phorus paid  nearly  200  percent  on  the  investment  in  steamed  bone 
meal  when  used  in  addition  to  nitrogen,  the  profit  is  more  than  offset 
by  the  nitrogen  deficit. 

On  another  part  of  Mascoutah  field  investigations  we^e  conducted 
to  secure  information  in  regard  to  the  practicability  of  securing  nitro- 
gen by  the  less  expensive  practice  of  growing  legumes  in  the  rotation 
and  returning  to  the  soil  the  crop  residues  and  farm  manure.  A 
comparison  of  these  results  for  eight  years  shows  that  the  crop  values 


1916] 


SUMMARY  OP  ILLINOIS  SOIL  INVESTIGATIONS 


477 


TABLE  1- 


-  VALUE  OF  CROPS  PER  ACRE  IN  FOURTEEN  YEARS,  DuBois  FIELD 
1902  TO  1915:    NOT  TILE-DRAINED 


Plot 

Soil  treatment  applied 

Total  value  of  14  crops 

Lower 

prices 

Higher 
prices 

101 
102 

$63.83 
88.28 

$91.19 
126.11 

Lime   

103 
104 
105 

Lime)  residues  

113.66 
145.66 
144.97 

162.37 
208.09 
207.10 

Lime,  phosphorus    

Lime,  potassium    

106 
107 
108 

Lime,  residues,  phosphorus  

165.07 
172.34 
186.02 

235.82 
246.20 
265.75 

Lime    residues    potassium   

Lime,  phosphorus,  potassium  -.  

109 
110 

Lime,  residues,  phosphorus,  potassium  

196.39 
140.50 

280.55 
200.71 

E«sidues.  Dhosohorus.  Dotassium.  . 

Value  of  Increase  per  Acre  in  Fourteen  Years 


For  lime 

For  residues    

For  phosphorus  

For  residues  and  phosphorus  over  phosphorus 

For  phosphorus  and  residues  over  residues 

For  potassium,   residues,    and   phosphorus   over    residues 
and  phosphorus 


$24.45 
25.38 
57.38 
19.41 
51.41 

31.32 


$34.92 
36.26 
81.98 
27.73 
73.45 

44.73 


at  the  lower  prices  averaged  $119.38  where  commercial  nitrogen  cost- 
ing $120  was  used,  and  $119.61  and  $117.20  where  residues  and  farm 
manure,  respectively,  were  used. 

These  data  show  that  practically  the  same  gross  values  are  secured 
with  "home-grown"  nitrogen  as  with  the  purchased  product,  and  at 
much  less  cost.  (Detailed  data  in  regard  to  crop  yields  will  be  found 
in  Soil  Report  8,  Bond  county.) 

Gray  Silt  Loam  on  Tiglit  Clay  of  Lower  Illinoisan 
Glaciation  (330) 

DuBois  Field. — Data  are  presented  in  Tables  7  and  8  showing 
the  results  of  soil  experiments  and  tile  drainage  upon  gray  silt  loam 
on  tight  clay,  the  common  prairie  soil  of  southern  Illinois. 

A  summary  of  these  data  shows  that  tile  drainage  has  paid  $6.37 
per  acre  in  fourteen  years,  or  45  cents  per  acre  per  year.  It  would 
require  at  least  $1.20  per  acre  per  year  to  pay  6  percent  interest  on 
the  cost  of  the  tile  drainage,  assumed  to  be  $20  per  acre. 

A  summary  of  the  average  results  from  the  tiled  and  the  untiled 
land  for  the  fourteen  years  shows  a  crop  value  of  $63.40  per  acre 
from  the  unfertilized  land,  and  increases  for  additions  as  follows : 

For  lime  alone $30.39  or  48  percent 

For  nitrogen  and  organic  matter  over  lime.  . . .   24.26  or  26 

For  phosphorus  as  a  further  addition 54.39  or  46 

For  potassium  as  a  final  addition 22.37  or  13 

For  total  increase  over  untreated  land $131.41  or  207  percent 


478 


BULLETIN  No.  193 


[December, 


TABLE  8. — VALUE  OF  CROPS  PER  ACRE  IN  FOURTEEN  YEARS,  DuBois  FIELD 
1902  TO  1915:  TILE-DRAINED 


Plot 

Soil  treatment  applied 

Total  value  of  14  crops 

Lower 
prices 

Higher 
prices 

111 

112 

None                 

$62.98 
99.32 

$89.97 
141.89 

Lime   

113 
114 
115 

Lime,  residues   

122.47 
136.54 
146.48 

174.96 
195.06 
209.26 

Lime,  phosphorus    

Lime,  potassium    . 

116 
117 
118 

Lime,  residues,  phosphorus  

179.84 
181.45 
193.43 

256.89 
259.22 
276.33 

Lime,  residues,  potassium  

Lime,  phosphorus,  potassium  

119 

120 

Lime,  residues,  phosphorus,  potassium  

193.26 
164.70 

276.08 
235.29 

Residues.  phosphorus,  potassium.  . 

Value  of  Increase  per  Acre  in  Fourteen  Years 


For  lime 

For  residues    

For  phosphorus  

For  residues  and  phosphorus  over  phosphorus 

For  phosphorus  and  residues  over  residues 

For  potassium,   residues,    and    phosphorus    over    residues 
and  phosphorus 


$36.34 
23.15 
37.22 
43.30 
57.37 

13.42 


$51.92 
33.07 
53.17 
61.83 
81.93 

19.19 


These  results  harmonize  with  those  that  would  be  expected  from 
the  chemical  composition  of  the  soil.  It  is  likely  that  as  the  organic- 
matter  content  of  the  soil  increases,  the  effect  of  the  potassium  will 
be  diminished. 

Fairfield  Field. — Upon  the  experiment  field  located  near  Fair- 
field,  Wayne  county,  on  typical  gray  silt  loam  on  tight  clay,  a  four- 
year  rotation  of  corn,  cowpeas  or  soybeans,  wheat,  and  clover  is  prac- 
ticed upon  four  independent  series  of  plots.  Live-stock  and  grain 
farming,  with  the  use  of  limestone  and  rock  phosphate,  are  practiced 
upon  tiled  and  untiled  land.  In  Table  9  the  results  from  the  field  as 
a  whole  for  eight  years  are  concisely  summarized  by  rotations.  (For 
more  detailed  information,  see  Soil  Report  No.  8,  Bond  county.) 

Here  untreated  well-rotated  land  produced  $19.69  per  acre  in  four- 
years  at  the  lower  values,  while  the  land  receiving  farm  manure, 
ground  limestone,  and  fine-ground  raw  rock  phosphate  produced  $53.04 
in  the  second  rotation.  If  it  costs  $5  an  acre  a  year  to  farm  the  un- 
treated land,  the  returns  lack  8  cents  of  paying  the  cost,  leaving  noth- 
ing for  taxes  and  interest;  moreover  this  land  is  becoming  poorer 
each  year. 

From  the  standpoint  of  tile  drainage  the  value  of  the  increase, 
at  the  lower  prices,  has  been  $1.08  per  acre  for  each  of  the  eight 
years.  It  would  take  at  least  $1.50  an  acre  a  year  to  pay  6  percent 
interest  on  the  cost  of  the  tile  drainage  at  $25  per  acre.  During  the 
last  four  years  of  tile  drainage,  the  increase  was  $1.79  per  acre  per 


1916] 


SUMMARY  OF  ILLINOIS  SOIL  INVESTIGATIONS 


479 


TABLE  9. — CROP  VALUES  PER  ACRE,  FAIRFIELD  FIELD 
1905  TO  1912 


First  Kotation:  Average  of  Four  Series 


Soil  treatment.  . 

None 

Farm  manure 

Limestone 
Phosphate 

Farm  manure 
Limestone 
Phosphate 

Lower 
prices 

Higher 
prices 

Lower 
prices 

Higher 
prices 

Lower 
prices 

Higher 
prices 

Lower 
prices 

Higher 
prices 

Value  of  4  crops 

$19.69 

$28.14 

$24.34 

$34.76 

$26.91 

$38.44 

$36.42 

$52.03 

Second  Kotation:    Average  of  Four  Series 


Soil  treatment  .  . 

Crop  residues 

Farm  manure 

Crop  residues 
Limestone 
Phosphate 

Farm  manure 
Limestone 
Phosphate 

Value  of  4  crops 

Lower 
prices 

$20.25 

Higher 
prices 

$28.92 

Lower 
prices 

$25.45 

Higher 
prices 

$36.36 

Lower 
prices 

$38.14 

Higher 
prices 

$54.49 

Lower 
prices 

$53.04 

Higher 
prices 

$75.79 

year,  which  would  pay  a  fair  rate  of  interest  providing  the  cost  of  the 
drainage  did  not  exceed  $30  per  acre.  Tile  drainage  may  ultimately 
prove  to  be  profitable. 

UPLAND  TIMBER  SOILS 
Yellow-Gray  Silt  Loam  of  Lower  Illinoisan  Glaciation  (334) 

Raleigli  Field. — Upon  the  experiment  field  located  at  Raleigh, 
Saline  county,  on  typical  yellow-gray  silt  loam,  a  four-year  rotation 
of  wheat,  corn,  oats  and  clover  (or  cowpeas  or  soybeans)  is  practiced. 
As  an  average  of  duplicate  trials  each  year,  the  crop  values  for  the 
years  1911-1914  from  four  acres  were,  at  the  lower  prices,  $16.44  from 
untreated  land,  $18.22  where  organic  manures  were  applied  in  pro- 
portion to  the  amount  of  crops  produced,  and  $33.58  where  6  tons  per 
acre  of  limestone  and  organic  manure  were  applied.  Owing  to  the 
low  supply  of  organic  matter,  phosphorus  produced  almost  no  benefit. 
However,  writh  increasing  applications  of  organic  matter  the  effect  of 
phosphorus  is  becoming  more  apparent. 

Yellow-Gray  Silt  Loam  of  Late  Wisconsin  Glaciation  (1234) 

Antiocli  Field. — The  Antioch  experiment  field  located  upon  yel- 
low-gray silt  loam  of  the  late  Wisconsin  glaciation  was  so  planned  that 
the  effect  of  various  additions  might  be  known  as  quickly  as  possible. 
The  elements  nitrogen,  phosphorus,  and  potassium  were  applied  in 
commercial  form  until  1911,  after  which  commercial  nitrogen  was 
discontinued  and  crop  residues  substituted. 

Altho  the  soil  is  somewhat  irregular  and  some  abnormal  seasons 


480 


BULLETIN  No.  193 


[December, 


TABLE  10. — VALUE  OF  CROPS  PEE  ACRE  IN  THIRTEEN  YEARS,  ANTIOCH  FIELD 

1902  TO  1914 


Plot 

Soil  treatment  applied 

Total  value  of  13  crops 

Lower 
prices 

Higher 
prices 

101 
102 

None   

$135.12 
119.74 

$193.03 
171.06 

Lime   

103 
104 
105 

Lime,  nitrogen  

124.70 
202.20 
138.88 

178.15 

288.85 
198.40 

Lime,  phosphorus    

Lime,  potassium    

106 
107 
108 

Lime,   nitrogen,   phosphorus  

179.41 
133.54 
201.35 

256.31 
190.77 
287.65 

Lime,  nitrogen,  potassium  

Lime,  phosphorus,  potassium  

109 
110 

Lime,  nitrogen,   phosphorus,   potassium  

191.22 
181.18 

273.18 
258.83 

Nitroeren.  phosphorus,  potassium.  . 

Value  of  Increase  per  Acre  in  Thirteen  Years 


For  nitrogen 

For  phosphorus 

For  nitrogen  and  phosphorus  over  phosphorus 

For  phosphorus  and  nitrogen  over  nitrogen 

For  potassi/um,  nitrogen,   and  phosphorus   over   nitrogen 
and  phosphorus    


$  4.96 
82.46 

-22.79 
54.71 

11.81 


$  7.09 

117.79 

-32.54 

78.16 

16.87 


have  caused  almost  complete  crop  failures,  the  general  summary 
strongly  confirms  the  analytical  data  in  showing  the  need  of  applying 
phosphorus,  and  the  profit  from  its  use,  and  the  loss  in  adding  potas- 
sium. 

In  most  cases  commercial  nitrogen  damaged  the  small  grains  by 
causing  the  crop  to  lodge.  From  the  results  of  other  fields  we  must 
conclude  that  better  yields  are  to  be  secured  by  providing  nitrogen 
by  means  of  farm  manure  and  legume  crops  grown  in  rotation  than 
by  the  use  of  commercial  nitrogen,  which  is  evidently  too  readily 
available,  causing  too  rapid  growth  and  consequent  weakness  of  straw. 
Table  10  gives  the  summarized  results  for  thirteen  years.  (For  more 
detailed  information  see  Soil  Report  No.  9,  Lake  county,  or  No.  10, 
McLean  county.) 

Yellow  Silt  Loam  of  Unglaciated  Areas  (135) 
of  Upper  Illinoisan  Glaciation  (535) 

Pot-Culture  Experiments. — Yellow  silt  loam  soil  collected  from 
an  unglaciated  area  and  from  the  upper  Illinoisan  glaciation  was  ar- 
ranged in  two  series  of  ten  four-gallon  jars  for  greenhouse  culture 
work  and  treated  by  additions  in  the  same  manner  as  for  field-culture 
work. 

As  an  average,  the  nitrogen  applied  produced  a  yield  about  eight 
times  as  large  as  that  secured  without  the  addition  of  nitrogen.  To 
determine  whether  "home-grown"  nitrogen  would  be  as  efficient  as 


1516] 


SUMMARY  OF  ILLINOIS  SOIL  INVESTIGATIONS 


481 


commercial  nitrogen,  other  pots  were  arranged,  and  to  some  commer- 
cial nitrogen  was  applied,  and  in  others  cowpeas  were  grown  and 
turned  under.  The  increase  due  to  commercial  nitrogen  was  not  suffi- 
cient to  cover  the  cost  of  the  application.  After  the  second  crop  of 
cowpeas  had  been  turned  under,  the  legume  manures,  as  an  average, 
made  rather  better  results  than  the  commercial  nitrogen.  These  re- 
sults confirm  the  analytical  data  in  showing  the  great  need  for  nitro- 
gen ;  and  they  further  show  that  such  nitrogen  need  not  be  purchased. 
Vienna  Field. — Since  yellow  silt  loam  is  subject  to  erosion  and 
washing,  the  control  of  these  factors  is  exceedingly  important.  The 
experiments  carried  on  at  Vienna,  Johnson  county,  upon  an  unglaci- 
ated  area  of  this  type  of  soil  are  conducted  solely  in  the  interest  of 
these  problems.  The  management  of  this  field  includes  deep  plowing, 
contour  plowing,  the  use  of  cover  crops,  the  increase  of  the  organic- 
matter  content  of  the  soil,  and  the  use  of  limestone.  Some  of  the  re- 

TABLE  11. — CROP  YIELDS  PER  ACRE  FROM  EECLAIMED  ABANDONED  HILL  LAND 

VIENNA  FIELD 


Year 

Field  1 

Field  2 

Field  3 

Field  4 

1906 
1907 
1908 

Corn   20.4  bu. 
Cowpeas  turned 
Wheat  7.9  bu. 

Cowpeas  turned 
Wheat  9.6  bu. 
Clover  .77  ton 

Clover  1.00  ton 
Corn  33.5  bu. 

Corn  24.4  bu. 
Cowpeas  turned 

1909 
1910 
1911 

Clover  .60  ton1 
Corn  38.6  bu. 

Corn  37.8  bu. 
Cowpeas  turned 
Wheat  17.6  bu. 

Cowpeas  turned 
Wheat  15.6  bu. 

Wheat  8.8  bu. 
Clover  1.53  tons 
Corn  32.8  bu. 

Average  Yields  of  Crops  Grown 


Corn 

Wheat 

Clover 

1906-1908 
1909-1911 

26.1  bu. 
36.4  bu. 

8.8  bu. 
14.0  bu. 

.89  ton 
1.07  tons 

irThe  yield  of  clover  for  1909  is  estimated,  the  weights  not  having  been  taken 
because  of  a  misunderstanding. 

suits  obtained  upon  this  field  are  recorded  in  Table  11.  They  show 
that  such  land  may  be  reclaimed  and  made  to  produce  fair  crops, 
which  tend  to  increase  when  proper  care  is  taken  to  reduce  washing 
and  limestone  is  used  in  connection  with  a  good  rotation. 

SWAMP  AND  BOTTOM-LAND  SOILS 
Deep  Peat  of  Sand,  Late  Swamp  and  Bottom  Lands  (1401) 

Manito  Field. — Table  12  records  the  results  obtained  from  the 
Manito  experiment  field  upon  deep  peat  soil,  where  experiments  were 
begun  in  1902  and  discontinued  in  1905.  These  results  are  in  harmony 
with  the  information  furnished  by  the  analysis  of  peat  soil  as  com- 
pared with  the  composition  of  ordinary  normal  soils.  Where  potas- 
sium was  applied,  the  yield  was  three  to  four  times  as  much  as  where 


482 


BULLETIN  No.  193 


[December, 


TABLE  12. — CORN  YIELDS  IN  SOIL  EXPERIMENTS,  MANITO  FIELD:  1902  TO  1905 

(Bushels  per  acre) 


Plot 

Soil  treatment 
for  1902 

Corn 
1902 

Corn 
1903 

Soil  treatment 
for  1904 

Corn 
1904 

Corn 
1905 

Four 
crops 

1 

None    

10.9 

8.1 

None    

17.0 

12.0 

48.0 

2 

None    

10.4 

10.4 

Limestone,  4000  Ibs.  .  . 

12.0 

10.1 

42.9 

3 

Kainit,  600  Ibs  

304 

32.4 

I  Limestone,  4000  Ibs.   / 

49.6 

47.3 

159.7 

I  Kainit,  600  Ibs  ) 

1  Kainit,  1200  Ibs  ....   f 
j  Kainit,  1200  Ibs.  ...   1 

5 

f  Aeidulat'd  bone,  350  Ibs.  \ 
Potassium   chlorid, 
200  Ibs  

30.3 
31.2 

33.3 
33.9 

)  Steamed  bone,  395  Ibs.  \ 
Potassium  chlorid, 
400  Ibs  

53.5 
48.5 

47.6 
52.7 

164.7 
166.3 

6 

Sodium  chlorid,  700  Ibs.  . 

11.1 

13.1 

None    

24.0 

22.1 

70.3 

7 

Sodium  chlorid,  700  Ibs.  . 

13.3 

14.5 

Kainit,  1200  Ibs  

445 

47.3 

8 

Kainit,  600  Ibs  

36.8 

37.7 

Kainit,  600  Ibs  

44.0 

46.0 

164.5 

9 

Kainit,  300  Ibs  

26.4 

25.1 

Kainit,  300  Ibs  

41.5 

32.9 

125.9 

10 

None    

14.91 

14.9 

None    

26.0 

13.6 

69.4 

Estimated  from  1903; 
standing. 


no  yield  was  taken  in  1902  because  of  a  misunder- 


nothing  was  applied.  Sodium  chlorid  (common  salt,  containing  no 
potassium)  produces  no  results  and  cannot  therefore  take  the  place 
of  the  potassium  salts.  Applications  of  limestone  produced  no  effect 
either  alone  or  in  combination. 

Sand  Soil  of  Sand,  Late  Swamp  and  Bottom  Lands  (1481) 

Green  Valley  Field. — For  six  years  experiments  were  conducted 
at  Green  Valley,  Tazewell  county,  upon  sand  soils  that  easily  drifted 
by  wind  when  not  protected  by  vegetation.  During  that  time  (1902 
to  1907),  a  four-year  rotation  of  corn,  corn,  oats,  and  wheat  was  prac- 
ticed upon  a  series  of  ten  plots  so  treated  as  to  secure  information  as 
rapidly  as  possible  upon  the  needs  of  the  soil.  The  summary  of  the 
six  years'  results  are  given  in  Table  13. 

From  these  results  it  is  plain  that  nitrogen  is  the  element  of  first 
importance.  In  fact  the  increase  in  yields  was  practically  sufficient 
to  cover  the  cost  of  the  commercial  nitrogen.  Potassium  is  evidently 
the  second  limiting  element  where  decaying  organic  matter  is  not 
provided,  but  the  limit  of  potassium  is  very  far  above  the  nitrogen 
limit.  Phosphorus  during  the  six  years'  time  produced  but  little 
increase. 

From  the  results  of  other  experiments,  it  is  clear  that  the  growing 
of  legume  crops  and  the  use  of  manure  (and  possibly  limestone)  on 
these  well-drained  sand  soils  can  well  take  the  place  of  commercial 
nitrogen.  Potassium  may  prove  profitable,  at  least  until  more  organic 
matter  is  supplied. 


1916] 


SUMMARY  OF  ILLINOIS  SOIL  INVESTIGATIONS 


483 


TABLE  13. — CROP  YIELDS  IN  SOIL  EXPERIMENTS,  GREEN  VALLEY  FIELD 
1902  TO  1907 


Plot 

Soil  treatment  applied 

Corn 
1902 

Corn 
1903 

Oats 
1904 

Wheat 
1905 

Corn 
1906 

Corn 

1907 

Value  of  6  crops 

Bushels  per  acre 

Lower 
prices 

Higher 
prices 
$134.78 
112.11 

401 

402 

None  

68.7 
68.2 

56.3 

42.0 

65.4 
24.9 
20.1 

49.7 
35.9 

18.3 
19.0 

32.9 

17.8 

35.3 
29.5 

$94.35 

78.48 

Lime  

403 
404 
405 

Lime,  nitrogen  

68.6 
30.3 
23.1 

44.4 
20.3 
16.9 

23.5 
16.7 
16.5 

62.9 
10.4 
8.4 

58.9 
13.1 

12.8 

127.74 
44.92 
38.82 

182.48 
64.17 
55.46 

Lime,  phosphorus  

Lime,  potassium  

406 
407 
408 

Lime,  nitrogen,  phosphorus 
Lime,  nitrogen,  potassium. 
Lime,  phosphorus,   potas- 
sium   

57.4 
70.0 

49.8 

69.8 
72.9 

39.6 

51.9 
54.7 

36.9 

26.8 
36.5 

13.7 

70.8 
74.8 

18.3 

64.7 
73.6 

2Y.7 

125.34 
142.82 

67.31 

178.91 
204.03 

96.16 

409 
410 

Lime,  nitrogen,  phosphor- 
us, potassium  

69.5 
57.2 

69.8 
66.1 

47.8 
50.0 

36.2 
26.5 

66.4 

66.0 

73.6 
71.9 

136.47 
123.97 

194.97 
177.10 

Nitrogen,  phosphorus, 
potassium  

Aver; 
Aver; 

0 

Aver, 
o 

ige  gain  for  nitrogen.  .... 

23.5 
6.8 
-5.9 

37.8 
3.8 
.7 

22.3 
3.1 
3 

14.3 
11.2 

1.5 

55.0 
3.8 
-3 

46.9 
11.8 
29 

$73.37 
17.88 
.22 

$104.82 
25.54 
.32 

ige   gain   for   potassium 
per  nitrogen  

ige  gain  for  phosphorus 
per  nitroeren  .  . 

PERMANENT  AGRICULTURE 

The  objective  which  all  farmers  should  then  hold  before  them  is 
the  establishing  of  practical  systems  of  soil  management  by  means  of 
which  the  fertility  of  the  soil  will  not  be  impoverished  but  will  be 
increased,  or  at  least  maintained,  thereby  making  agriculture  perma- 
nent. 

On  some  soils,  such  as  yellow  silt  loam,  where  erosion  by  surface 
washing  is  carried  on  to  a  great  extent,  a  low-grade  system  of  perma- 
nent agriculture  can  be  maintained  if  some  use  is  made  of  legume 
crops  in  long  rotations,  with  much  pasture.  This  system  will  furnish 
sufficient  nitrogen  and  organic  matter  and  the  minerals  will  be  main- 
tained by  the  renewal  of  the  surface  soil  from  the  subsoil  by  erosion. 
It  is,  however,  the  privilege  and  duty  of  farmers  upon  the  common 
soils  of  the  state  to  establish  a  high-grade  system  of  permanent  agri- 
culture and  hand  it  down  to  posterity.  Abundant  information  shows 
that  this  can  be  done :  first,  by  making  liberal  use  of  legume  crops  in 
a  good  rotation ;  second,  by  applying  limestone  liberally  to  soils  that 
are  acid  or  bordering  upon  acidity ;  and  third,  by  using  finely  ground 
raw  rock  phosphate  in  amounts  larger  than  are  necessary  for  present 
needs,  until  the  soil  is  well  supplied  with  the  element  phosphorus. 

For  further  and  more  detailed  information  regarding  the  soils  of 
the  state  and  methods  for  their  improvement,  the  reader  is  urged  to 
send  to  the  Illinois  Agricultural  Experiment  Station  for  any  of  the 
soil  reports,  bulletins,  or  circulars  listed  on  the  following  page. 


484  BULLETIN  No.  193  [December, 


AVAILABLE   PUBLICATIONS  RELATING  TO  ILLINOIS  SOIL 
INVESTIGATIONS 

No.  BULLETINS 

76  Alfalfa  on  Illinois  Soils.    1902   (5th  ed.,  1913). 
157  Peaty  Swamp  Lands;    Sand  and  "Alkali"  Soils.    1912. 
177  Eadium  as  a  Fertilizer.    1915. 

181  Soil  Moisture  and  Tillage  for  Corn.    1915. 

182  Potassium  from' the  Soil.    1915. 

190  Soil  Bacteria  and  Phosphates.     1916. 

CIRCULARS 

110  Ground  Limestone  for  Acid  Soils.    1907   (3d  cd.  1912). 

123  The  Status  of  Soil  Fertility  Investigations.    1908. 

127  Shall  We  Use  Natural  Rock  Phosphate  or  Manufactured  Acid  Phosphate  for 

the  Permanent  Improvement  of  Illinois  Soils?    1909   (3d  ed.  1912). 
130  A  Phosphate  Problem  for  Illinois  Landowners.   1909. 

142  European  Practice  and  American  Theory  Concerning  Soil  Fertility.    1910. 
145  The  Story  of  a  King  and  Queen  (Corn  and  Clover).    1910. 
150  Collecting  and  Testing  Soil  Samples.    1911   (4th  ed.  1916). 
155  Plant  Food  in  Relation  to  Soil  Fertility.    1912. 
165  Shall  We  Use  "Complete"  Commercial  Fertilizers  in  the  Corn  Belt?     1912 

(4th  ed.  1913). 

167  The  Illinois  System  of  Permanent  Fertility.    1913. 

168  Bread  from  Stones.    1913. 

181  How  Not  to  Treat  Illinois  Soils.     1915. 

185  A  Limestone  Tester.     1916. 

186  The  Illinois  System  of  Permanent  Fertility  from  the  Standpoint  of  the  Prac- 

tical Farmer:  Phosphates  and  Honesty.     1916. 

SOIL  REPORTS 

No.  1  Clay  County.    1911.  No.  6  Knox  County.    1913. 

No.  2  Moultrie  County.    1911.  No.  7  McDonough  County.    1913. 

No.  3  Hardin  County.    1912.  No.  8  Bond  County.    1913. 

No.  4  Sangamon  County.    1912.  No.  9  Lake  County.    1915. 

No.  5  LaSalle  County.    1913.  No.  10  McLean  County.    1915. 

NOTE. — Subsequent  to  the  preparation  of  this  bulletin,  the  following  soil  re- 
ports have  been  published: 

No.  11  Pike  County.    1915.  No.  13  Kankakee  County.    1916. 

No.  12  Winnebago  County.     1916.  No.  14  Tazowell  County*    1916. 


UNIVERSITY  OF  ILLINOIS-URBANA 


